Home / Remove Squirrels / How to get rid of squirrels

How to get rid of squirrels

Overview:

  • Squirrels are trouble.
  • There are a lot of different methods available to get rid of squirrels, each with their own pluses and minuses.
  • I am putting this article together in hopes that it will be a foundation on which we can build.  Please share your tips and insight in the comments section of this article so others can benefit from your experience.
  • Hopefully this article can become a place where we can share ideas in the way that the article on gopher resistant plants is becoming.

 

Why get rid of squirrels?

  • As you may have recently read, squirrels can carry and transmit the Bubonic Plague!  This disease is also known as the Black Death and it is the scourge that killed half of the people in Europe during the middle ages. Please see my recent plague warning article.
  • This might be reason enough to get rid of this menace, but there are many more reasons.
  • These rodents are also very destructive.  They will tear your yard apart, chew through irrigation lines, eat your plants, and steal your produce.  They can also do serious structural damage to foundations and to retaining walls.  Of course their holes can also be a walking hazard.
  • These destructive rodents seem to bubble up from the ground like some sort of evil spawn.  They will not go away on their own.  Its better to act fast than to wait.  It is easier and less expensive to control a small population.  If you do nothing, they will take over.
This pic is from the Huffington post article: "Squirrel Vandalized Bikes At Iowa College" http://www.huffingtonpost.com/2013/10/25/squirrel-vandalized-bikes_n_4164957.html

This pic is from the Huffington post article: “Squirrel Vandalized Bikes At Iowa College” http://www.huffingtonpost.com/2013/10/25/squirrel-vandalized-bikes_n_4164957.html

An inguinal bubo on the upper thigh of a person infected with bubonic plague. Swollen lymph glands (buboes) often occur in the neck, armpit and groin (inguinal) regions of plague victims.Photo credit wikipedia.

An inguinal bubo on the upper thigh of a person infected with bubonic plague. Swollen lymph glands (buboes) often occur in the neck, armpit and groin (inguinal) regions of plague victims.Photo credit wikipedia.

 

Evidence of squirrels living in your area:

  • These varmints can be rather stealthy and may be hard to spot.  However, they do leave a characteristic imprint on the area where they vandalize.
  • The California ground squirrel, (Spermophilus beecheyi) is a burrowing animal.  It prefers to dig its den under large boulders, rocks and wood piles. Foundations of homes/structures are also on their list of preferred sites.  In the process of digging out their dens, they can damage all kinds of important things for your house.  In addition, once they make that burrow-hole, other animals such as snakes and poisonous bugs can also move in.
  • The holes for their burrows are usually 4 to 6 inches in diameter.  They also usually leave the burrows open for a quick getaway.  This open characteristic will distinguish their holes from those of gophers or moles.
  • Ground squirrels typically live and forage within a 75-yard radius of their burrow.
  • Ground squirrels live in colonies that can include several dozen animals in a complex of burrows. More than one squirrel can live in a burrow.
  • These guys will also eat all kinds of plants and even bird eggs. I have noticed that a staple dish for them seems to be the fruit of the ubiquitous ice plant.
  • Ground squirrels are active during the day, mainly from midmorning through late afternoon
My poor mullberry tree eaten by a squirrel. Broken branches ans a few remaining hard to get leaves at the ends of branches are a telltale signs.

My poor mullberry tree eaten by a squirrel. Broken branches and a few remaining hard to get to leaves at the ends of branches are a telltale signs.

Squirrel retaining wall damage

Ground squirrel making its home in a retaining wall. This can obviously lead to major structural problems.

Evidence of squirrels eating ice plant fruit

Evidence of squirrels eating ice plant fruit. Ice plant flower and fruit to the left and eaten remains of fruit to the right

Squirrel rocky perch with remains of eaten iceplant fruit

Squirrel rocky perch with remains of eaten ice plant fruit scattered about

Squirrels love to live under large rocks and structures. The one in this picture moved into an opossum den under a building. http://www.nhm.org/nature/nature_blog_archive/2012

Squirrels love to live under large rocks and structures. The one in this picture moved into an opossum den under a building.
http://www.nhm.org/nature/nature_blog_archive/2012

 

How to get rid of squirrels:

  • The following excerpt is from the University of California agriculture & natural resources.   The California Fish and Game Code classifies ground squirrels as nongame mammals. An owner or tenant can control, in any legal manner, nongame mammals that are injuring growing crops or other property; tree squirrels, on the other hand, are classified as game animals and have a hunting season.  No license is required if it is the owner or tenant who is taking ground squirrels that are causing damage. A trapping license from the California Department of Fish and Game is required for those who are trapping squirrels for hire or profit.
  • Note: different methods are more effective at different times of the year. See table below.

When to Use Specific Controls

 

  • Below I will highlight some methods that I am familiar with. This is by no means meant to be a complete list.  If you have additional ideas and/or success with other methods please let me know in the comments section and I will add it to the list.

 

(note: The U. S. Fish and Wildlife Service classifies the Mohave ground squirrel, S. mohavensis, and the San Joaquin antelope squirrel, Ammospermophilus nelsoni, as threatened species; therefore both are protected animals. Although you are unlikely to misidentify either of these relatively small squirrels as the much larger California ground squirrel, their ranges could overlap in some areas).

Squirrel harassment:

Ground squirrels live in burrows that they dig out or take over from other animals.  They also don’t like to wander too far from the safety of that nest. Therefore, I have recently employed a policy of harassment.   I have been filling the holes with all kinds of strong smelling things to kick them out. I have also been filling the holes back with soil.

Results:

Ammonia doesn’t seem to do much, Chili pepper flakes and Sriracha is mildly effective for a few days. The best option that I have noticed is to shove some wire cloth/mesh down the hole and cover it up with soil. For this purpose, I use the same type of wire cloth material that I use for making gopher cages. These rodents also like to make their home in piles of wood, rocks, trash, etc. Therefore, removing these potential living areas is also key.  It is also a great idea to repair all holes or other routs of entry into your home.  You want to make sure they cant get into your house, garage or attic.

Positives: Cheap, and a good idea regardless.  Squirrel holes may be abandoned for a variety of reasons. However, filling it back up with soil will help to prevent another squirrel from taking it over.  Getting rid of the holes will also help to keep other unwanted animals out.

Negatives: This process takes some time and effort. Where there is one hole, there is usually at least another; (they like to have multiple escape routs).  However, just removing their dens will not remove the threat.  These guys can be persistent.  In addition, you may potentially become exposed to contaminated soil when messing with their dens. Please refer to CDC protective clothing recommendations. Note, other dangerous creatures such as rattlesnakes, spiders and scorpions also like to live in similar areas or take over old squirrel holes/burrows. Call a professional.

Food management:

If they don’t have food they are less likely to hang around. However, I have discovered that these vermin will eat just about anything.  They also do have a special preference for fruit, so picking your produce as soon as/or just before it is fully ripe can help. Cleaning up dropped fruit is also very important for this and other reasons.

Cleaning up and managing pet/livestock food is critical.  The fruit of the ice plant seems to be their ‘bread and butter’, so if you are looking for ‘ground cover’, I would consider another option.

Positives:  This is a good idea anyways and keeps other pests away.

Negatives: Picking your fruit too early is not always the best option. Sometimes those darn squirrels will just eat the fruit before it is ripe anyways.

Scare/Dissuade squirrels:

Using things like scare tape and mylar pinwheels is pretty effective at keeping the vermin off of your developing fruit in the short term.

Spraying leaves and fruit with water and then coating with chili powder or chili flakes works quite well at keeping them uninterested in your plants/fruit.

Positives: Organic, cheap, effective.

Negatives:  If this is all you do you will still have squirrels in your yard. They can get use to the scare tape if you leave it up all year. The chili power/flakes washes off in the rain.

Squirrel Traps:

There are live traps and kill traps available.

I recently got this small live animal trap on Amazon. It is actually pretty darn amazing… I can catch squirrels just about every day that I set the trap.  Unfortunately, there are significant drawbacks to using a live trap… and from my research it looks like I will have to stop using it (see discussion below).

So then there are kill traps.  The University of California agriculture & natural resources recommends using box traps, tunnel traps, and/or conibear traps.   The University of California agriculture & natural resources was pretty specific about the exact type of conibear trap to use and here is a link to one with great ratings on amazon. Conibear trap No. 110, with a 4 1/2- by 4 1/2-inch jaw spread.  However, the term “box trap” and “tunnel trap” is so generic that I dont feel confident providing a link to one of those at this point.

Positives:  Traps remove the vermin from your property. Good karma if you are using the no kill trap. In general traps work amazingly well.

Negatives:  This excerpt is from University of California agriculture & natural resources:  Traps are practical for control when squirrel numbers are low to moderate. Live-catch traps aren’t recommended, because they present the problem of how to dispose of the animals. Because ground squirrels carry diseases and are agricultural pests, the California Fish and Game Code specifies it is illegal to release them elsewhere without a written permit.

Note, a live squirrel in a trap needs to be treated with caution. These things are wild animals and have nasty large claws.

On the other hand, I have heard that some people will drop a live trap in water to drown the animal. Sure this would work, but in my mind kindof runs counter to idea of using a live trap.  So then we are left with the option of a kill trap.

The trapped squirrel (dead or alive) may also be carrying disease such as the plague; please refer to the recommendations in the CDC letter.

For more info on the subject ck out the info from the University of California agriculture & natural resources.

Squirrels are easy to catch with this rodent trap

Squirrels are easy to catch with this rodent trap

Squirrel Poison:

There are a lot of different poisons and bait stations that you can get for squirrels.  These bait station boxes must be tamper-resistant so small children are not able to access the contents.

Positives:  They are pretty easy to set up and maintain. A bait box will help to prevent unintended animals (like dogs or foxes)  from getting into the poison.

Negatives: Whatever poison you used to kill the squirrels is likely to be present in their dead body.  If another carnivore eats that poisoned-dead animal, they may also die or get very sick. In this regard you could be reducing the number of beneficial squirrel predators in your area.  Your cat or dog could also become ill this way.

Since the squirrels go into the bait station, they may potentially leave some hungry fleas behind, which could potentially be a problem for you when adding more bait to the station.  That being said, I have never actually heard of this happening.

Dogs:

The right dog can both kill and scare away squirrels. Protect your dogs from the risk of the plague as much as you can. Flea and Tick Control products are one of many options.

Positives: Dogs are always working to please you and get the job done.

Negatives:  Plague infected fleas could jump from the squirrel on to your dog… and then on to you.  Please take precaution.

Birds of prey:

Raptors such as owls and hawks are excellent at keeping rodent populations under control.

You can actually do some things to attract these beneficial birds such as building/installing barn owl boxes and perches for hawks.

Positives: Natural, cheap and effective

Negatives:  It can be hard to attract these birds of prey in some areas.

Air rifle:

There is an entire industry built around the use of high powered air rifles for rodent hunting and control.

I recently bought a truly awesome air rifle made by the German company RWS. I am extremely happy with it.  I also did a ton of research before I settled on this fantastic rifle.  You can even get this amazing RWS model 34 air rifle on Amazon if you are so inclined.

To date, I have only used this gun for target practice.  I want to see how far I can get with nonlethal methods… Yea, I know I am a softie.  However, it is very clear to me that this thing is as powerful and accurate as any small game hunting rifle.

Positives: These guns are very accurate and powerful. They are also relatively quiet compared to a traditional rifle.  This quite-ness may be beneficial if you do not wish to alarm your neighbors with the sound of gunfire and it may even allow you to take another shot if necessary.  Finally, the ammo is very very cheap.

Negatives: These guns are not toys and need to be treated with the same respect that you would give any other firearm.  Pellets or BBs can ricochet, rebound, bounce or skip off a surface.   Missing your rodent target could mean doing other damage that you did not intend to. Again, this is a powerful weapon to be respected and to be used with ultimate safety.  There may be local laws and ordinances restricting the use of these weapons in your area.  Please consult local laws before use.

The next issue is how to deal with the dead animal that is potentially infected. Please refer to the recommendations in the CDC letter in my recent article on the plague and ground squirrels.

When using firearms to manage squirrels, don’t use lead ammunition in areas within the historical California condor range.

Fumigation:

At this point I have no personal experience with fumigation control. Therefore, I have basically cut and pasted the recommendations on the subject  from University of California agriculture & natural resources article. The following is word for word from them as of today 9/17/14 (see below).

Fumigation is a relatively safe method of control. As with any pesticide, read and follow label instructions with particular regard for nontarget species and safety factors. Some fumigants can produce flames, creating a fire danger. Don’t use these types fumigants where a significant fire hazard exists, such as near buildings, dry grass, or other flammable materials. To prevent fumes from accumulating in enclosed areas, never fumigate beneath buildings or in burrows that might open beneath occupied buildings.

Be aware of the signs of nontarget species inhabiting inactive ground squirrel burrows. Kit foxes will use an old burrow, enlarging the opening, and often creating a keyhole-shaped entrance. Active pupping dens might contain prey remains, droppings, and matted vegetation and show signs of fresh paw prints. The burrowing owl (Athene cunicularia) is another potential occupant of abandoned ground squirrel burrows. Don’t treat a burrow if you suspect a nontarget animal is present. Fumigate only active ground squirrel burrows; county agricultural commissioners can provide additional information on how to recognize these.

Many county agricultural commissioners’ offices sell United States Department of Agriculture gas cartridges, which are designed for fumigating burrowing rodents. Other types of fumigation cartridges also are available at retail outlets. Fumigation is most effective in spring or other times when soil moisture is high, which helps contain the gas within the burrow system. Don’t fumigate in summer or when the soil is dry, because the gas more readily diffuses into small cracks present in dry soil, making it less effective. Don’t fumigate during hibernation, because the squirrel plugs its burrow with soil, preventing fumes from reaching the nest chamber; you can’t see this plug by examining the burrow entrance.

Treat all active burrow systems when fumigating. When using a USDA gas cartridge, puncture the end with a nail or screwdriver at the points marked, and rotate the nail to loosen the material inside. Insert the fuse into the center hole. Place the cartridge in the burrow as far as possible, and light the fuse. With a shovel handle or stick, push the lighted cartridge down the burrow, and quickly seal the opening with soil, tamping it down. Fill in connected burrows if you see smoke escaping. Larger burrow systems usually require 2 or more cartridges placed in the same or connecting burrow openings. After 24 hours, check for reopened burrows, and re-treat as needed.

June 12 2015 update: 

Irish Spring!

I have been reading that some people have used the soap Irish Spring to keep the Squirrel’s away. Apparently they don’t like the smell of that soap. The key seems to be to shred the soap in a cheese grater to extend the smell. I just tried this a few weeks ago and amazingly it seems to work! Here is a box of 8 bars of Irish Spring for cheap on amazon.

Irish Spring keeps squirrels away

Irish Spring keeps squirrels away

About Thomas Osborne, MD

Dr. Osborne is a Harvard trained Radiologist and Neuroradiologist who loves to share his insight about medicine and gardening.

46 comments

  1. It is illegal to move live rodents off your property (after catching them in cages) in the state of California. Also, those animals are dropped into a foreign territory to them and the resident rodents will kill them as invaders.

    • Thomas Osborne, MD

      Thanks for the info Connie. How do you deal with them?
      Thanks, Tom

      • My squirrels are tree squirrels they come on my deck and dig up my flower pots. They have ruined my pecan crop this year. Are they as bad for disease? I am in town with 4 officers around me. So no guns.this is the only pecan tree in several blocks. Any ideas?

        • Thomas Osborne, MD

          Hey Coleen
          What a pain!
          Your entire pecan crop!!!

          Yea, unfortunately, tree squirrels can harbor the same diseases.
          The good news is that you can trap and dispose of them.

          There are 4 species of tree squirrel recognized to be romping around in the daylight in California (2 introduced species and 2 native species).
          However, amazingly for 3 of the 4 you are suposto have a hunting license or permit to remove them from your property!
          Welcome to California.

          This the following is a direct cut-and-paste from the University of California Dep of Agriculture website.
          Tree squirrels are classified as game mammals by the state Fish and Game Code and can be controlled only as provided by the hunting regulations. Any owner or tenant of land or property that is being damaged or destroyed or is in danger of being damaged or destroyed by grey squirrels must apply to the California Department of Fish and Game for a permit to control such squirrels. The Department, upon receipt of satisfactory evidence of actual or immediately threatened damage or destruction, may issue a revocable permit for the removal and disposition of such squirrels. When a permit to trap the grey squirrel is issued, the Department may designate the type of trap to be used and may also require that squirrels be released in parks or other nonagricultural areas. It is not legal to use poison baits to kill tree squirrels. Eastern fox squirrels found to be injuring growing crops or other property may be controlled at any time and in any legal manner by the owner or tenant of the premises without a permit.

  2. I was delighted to read your latest article about squirrels. I used to be plagued by Gophers who I managed to get rid off by poison bait and wire mesh. Unfortunately they were replaced by a worse vermin – Squirrels. They are smart, persistent and multiply like rats. They first started at the perimeter, then got past the fence, then dug under a 50 feet long stone wall, and then dug under our house foundations. Not only have they invaded my land, but they have also plagued the entire neighborhood burrowing under the foundations and climbing into attics. I have bought and used 2 BB guns, 1 Rifle, 4 traps, and blocked off their holes with wire mesh laced with dried chillis. But they still keep coming and multiplying. They play on my lawn and bask on the wall and of course worst of all, eat all my apricots, cherries, peaches, almonds, apples, oranges, etc. They are driving me crazy. Any suggestions?

    • Thomas Osborne, MD

      Oh Sateesh!
      I am so sorry to hear about your terrible infestation.

      Squirrels are amazingly difficult to battle.
      I am with you, I thought gophers were bad till I got hit by the glorified rats called squirrels.

      They are pushing me to my limits as well.

      Its a tough battle to fight alone.
      I imagine that if you work really hard and rid your property of the vermin then the neighbors squirrel problem will just walk over.
      You will never win that battle.
      However, if you and your neighbors attack the problem together, in a coordinated effort, then you could wipe out an entire group of the raiding squirrels.

      Let me know if you have any other ideas.

      best,
      Tom

      • Thanks for your response Tom. Always good to hear your sage advice. My neighbors and I got together and we decided to take drastic action to rid ourselves of the pests. We are simply cutting back all our fruit trees to remove their food supply. They usually steal our fruit anyway, so in future no one gets any. It hurts me a great deal because you know how passionate I am about fruit tree gardening. But we have to get rid of these blighters since they have now gotten into our attics and under the foundations. The whole cul-de-sac is affected unfortunately. Lately I have seen more hawks or eagles circling overhead and for a week we looked after my daughter’s two yellow Labs which kept the pests at bay. Thanks for your help in my war against the varmints. Best regards, Sateesh

        • Thomas Osborne, MD

          Always great to hear from you Sateesh!

          Collaboration:
          Sounds like your on the right path to dealing with these destructive critters.
          Once those squirrels are embedded they can be very difficult to remove and collaboration with your neighbors is a key step.
          The importance of neighbor collaboration should not be understated and is a step that is often overlooked.
          Great job for taking the initiative.

          Neighbors:
          As you know, getting rid of their food supply is critical.
          However, as you know, that is just part of the plan.

          Other food:
          Your next potential issue is that those raiders will begin to look for other sources from food once the fruit runs out.
          They will strip a tree clean of all of its leaves.
          Yea, a real bummer.
          Mulberry tree leaves are often their first target.

          Physical removal:
          You really have to physically remove squirrels from the equation if you are going to have any relief… And at the same time destroy their dens so other cousin squirrels dont take their place.

          Good luck and please keep us posted!

  3. Last year we had quite the squirrel and rabbit problem. We bought several traps called “Squirrelinators.” We were able to trap all of the squirrels and then shoot them with a high powered air rifle right in the cage. The rabbits were a different story; we got up at sunrise around the time they start their early morning raids and would pick them off with same said air rifle. We are pretty much vermin free at this point. The occasional squirrel still shows up in a trap and now we dump it, live, in a trap and use it as bait to catch coyotes. Which again, we shoot, but this time with a 22. Of course, we have had some trouble with raccoons from time to time and shoot them once they are trapped. Trapping some of these animals is very easy; others not so easy.

  4. I’m kind of sad to hear all the squirrel killing. I have the smallest of the ground squirrels in my area and I thouroughly enjoy them. I admit I wasn’t too happy when they ate my succulents. The ones that visit me, usually just racing through, have stripped tails, stand frequently, and give my indoor cats loads of entertainment. You all will probably hate me but I feed them oatmeal, which they seem to enjoy. I was wondering if the cat urine sticks might help keep them away from your fruit trees. I was thinking of trying one of the fruit trees, like the dragon fruit but I think it’s too dry in Mesquite, NV, and I don’t want to fight the squirrels. Good luck with yours and I do wonder if a cat lounging in the garden might not be the best thing. Oh, the cat urine sticks are available at Zamzows in Boise, ID.

    • Thomas Osborne, MD

      Thanks for the note Janet.
      I understand what you are saying. I have not actually intentionally killed any squirrels yet myself… However, they are pushing me to my limit. So thank you for the “cat urine stick” suggestion. I have seen things that sounds similar such as a granular application that scares off animals with the odor. Any experience with something such as this? (link below has 3/5 star rating on Amazon)
      http://www.amazon.com/gp/product/B0016PC4TS/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=B0016PC4TS&linkCode=as2&tag=tastylands-20&linkId=QG25B5MNQ2R5UQRH“>Havahart Critter Ridder 3146 Animal Repellent, 5-Pounds Granular ShakerReply

      • Unfortunately, I do not. Another option may be to get a cat from your local shelter. They keep squirrels away also. Zamzows is an organic gardening center. You may want to talk with them before purchasing anything. Love your website. I just tried my first prickly pear fruit. Very interesting flavor. Absolutely gorgeous color.

        • Thomas Osborne, MD

          Thanks Janet.
          Thank you for your positive comments about the website.

          Outdoor cat solution:
          I have been thinking about getting an “outdoor” cat at the local animal shelter to address some of the rodents.
          However, we also have coyotes around here and cats are on their dinner menu.
          Do you happen to know of any outdoor-cat protection ideas?

          Cactus Fruit:
          Agree, prickly pear fruit is interesting and beautiful inside.
          However, I find the seeds to be a bit too hard.
          I have a few articles about some other awesome cactus fruit for you to try if you get a chance (links below).

          If you want an exceptional treat, try the dragon fruit cactus:

          Or Cereus Peruvianus:

  5. Squirrels can cause significant structural damage to buildings. It’s important to take preventative measures to limit your home’s accessibility. Immediately take action if a squirrel does get inside to avoid a full infestation – one squirrel can give birth to 5 kits every 6 months.

    • Thomas Osborne, MD

      Thanks Alfred, I agree Squirrels are very damaging.
      They not only cause structural damage… but they can also chew/ruin wires and spread disease.
      They are bad news around your home.

  6. How often should you replace the Irish Spring? Squirrels here have been eating up our trash can lids and chewing on the deck. We recently purchased a fake owl which we sit on the ledge. It’s only been a day so I’ll see how it’s working.

    • Thomas Osborne, MD

      Hey Sheryl
      Sorry to hear about your squirrel problem, they are so frustrating.

      Great question:
      I have noticed that the effects of Irish Spring soap lasts from one to two weeks depending on the location.
      Areas with intense direct sunlight seem to loose the effectiveness faster than areas that are shaded.
      I think that UV sunlight must be breaking down some of the soap perfumes and that is the cause of the difference.

      Hope this helps,
      Tom

  7. Thank you for this informative article. I live in AZ and noticed somebody was eating my prized pear cactus and at first thought it was a Javelina as the bite marks were so big but after further observation I discovered it was in fact ground squirrels that had invaded the plant as I could clearly see where rocks & soil had been strewn about to build their little caves. I love animals, it is their world too so I don’t want to hurt them but have visions of my pear cactus being totally devoured so I am going to try the Irish Spring soap idea and will report back. Thank you again.

    • Thomas Osborne, MD

      Your very welcome Dona
      I also feel rather conflicted about these voracious critters.
      Hope the Irish Spring works for you and looking forward to hearing back about your progress.
      Tom

  8. Central California Gold Country Foothills
    Our rural foothill property has always been surrounded by ground squirrels that were never a problem until the drought brought them to our yard. We are very close to the area where rodents are known to actually carry the Plague virus. Traditionally our problems have only been Deer but this year is different. Please note that we are not conflicted and will use almost anything short of a nuclear option.
    My first response was about $50.00 worth of “Rodent Destroyer” gas cartridges which were fun to use but ineffective.
    The next effort was a powerful pellet rifle which has been about 50% effective but the remaining squirrels are now very wary and hard to target. They even seem to know when I’m gone to work and spend those days openly eating, frolicking, and digging.
    My last effort involved making the equivalent to M80’s (1/2″ PVC pipe fittings w/ 1/2oz of FFg black powder and 15 sec fuse) in an effort to overpressure the critters in the tunnels. This was also fun, a little loud, & even caused the 40lb rock I used to cover the entrances to move a little with each blast. Unfortunately that seems to have been the only result. This would probably work with a larger charge but I suspect it might upset the neighbors and the Sheriff even more than the squirrels.
    Next week I will test a different less dramatic method. Using a large plastic funnel and hose I will place about 2lbs of Dry Ice pellets deep into each hole and then seal the entrances. The theory is as the heavier than air carbon dioxide (CO2) gas is slowly released it will sink into the deepest parts of the tunnels displacing the air and suffocated anything inside. Because the ground is so cracked, dry, and porous it may be only partially effective at best but I will learn something. When we get into fall and the El Nino rains have moistened the soil I think it will become a very effective option. While not a lot of fun at least this option will be cheap, quiet, non-toxic, politically correct, environmentally friendly, & leave no trace. The goal is to have no squirrels remaining to reproduce next spring.

    • Thomas Osborne, MD

      Hey Russ
      Thank you for the awesome comment!

      You have a great way with words… And I feel your pain.
      Those unforgiving critters are really turning it up in my area as well.
      I dont know if it was intentional, but the way you told your story made me laugh out loud.
      Thank you for adding some humor to a frustrating situation.

      I look forward to hearing more about your extermination experiments.
      Thanks,
      Tom

  9. Update on Aug 16th post!
    Yesterday at about 4:30PM I came home from work with about 15 LBs of Dry Ice. I couldn’t find any Dry Ice locally in the pellet form I wanted but ended up with blocks of about 5 LBs each. I broke up the blocks into fist sized chunks small enough to fit into the squirrel holes. With a lot of caution and very thick industrial leather welding gloves I placed about 2 Lbs into each hole and covered loosely with dirt. The temperature was 101 and I was hot & tired before even starting so I put very little effort into covering the holes. The theory is that as the cold dense CO2 gas is released being heavier than air will sink deep into the tunnel system displacing the oxygen and introduce the occupants to a permanent dream state. One pound of dry ice will produce 7+ cubic feet of pure CO2 gas so 2 lbs. x 7 cu/ft. x 7.48 gal/cu/ft.= 105 gallons of CO2 gas which should be adequate for any rodent tunnel.
    Eureka! (At least for us Californians) So far it has worked. It has been over 21 hours without any evidence of life from within the treated holes. One hole was reopened but the digging was obviously from the outside so it wasn’t an occupant. This was just supposed to be a trial run and involved only about half of my known active tunnels. Next weekend will be different!
    THE PLAN:
    G-Day -3 Locate and loosely cover every tunnel entrance on my 1+ acre lot.
    G-Day -1 Get an accurate count of active tunnels.
    G-Day Purchase at least 2lbs of dry ice for each active tunnel.
    Distribute equally and do a much better tunnel sealing & ground leveling job.
    G-Day +2 Celebrate? Well at least give another update here.
    CAUTION:
    If you decide to try using dry ice the following is critical.
    Dry ice is -100F and will instantly freeze any flesh it contacts. Use really serious gloves.
    CO2 gas isn’t toxic but being dense it will displace air/oxygen so have adequate ventilation.
    Do not transport dry ice in a closed vehicle. Either open the windows or put in a pick-up bed.
    Do not seal dry ice in any non-vented container. This is very dangerous so You say “I Obey” now.

    FYI: I paid $1.19 per Lb. for dry ice at a rural supermarket.

    Russ

    • Thomas Osborne, MD

      Russ, your a freekin genius!!!

      This is awesome; totally organic and cheap.

      Thank you for the awesome details and warnings as well.
      Very informative, and thoughtful.

      Many thank from all of us.

      Looking forward to hearing about the lasting results.

      Thanks,
      Tom

      • It has been 45 hours without any ground squirrel activity so at this point I must declare a small victory for man. A look at the calendar suggests that now is the time for action if you want to reduce/eliminate squirrel damage next spring. In most areas the squirrels will soon enter a dormant phase and seal off their underground nesting area by plugging the tunnel deep inside.
        HELP WANTED:
        Next week I will attempt total annihilation on my 1.1 acre piece of California but it would be really helpful if a few other people would quickly Beta test this method on other ground squirrel populations & in different locations. Only with more positive testing results can we declare this to be a viable and useful tool.
        Russ

  10. Just discovered this discussion and looks like about a year since anyone has commented, so hope you will see it! We live in southern CA foothills and we have been invaded by both ground and tree squirrels the last few years. We have a beautiful huge macadamia tree that used to give us buckets of nuts every years. Now we get none! They eat them before they are even ripe. Don’t know if you have ever tried to crack a macadamia nut, let me tell you the shell is extremely hard. The fact that the squirrels can chew and hole in these and get the meat out tells me they have jaws of steel. Scary!
    We usually trap them and then dispatch them to a better place with a pellet gun (non-lead pellets). However, I have had some luck with a Ratzapper. I usually set it at night in the barn to catch rats, but one day forgot to turn it off and was surprised to find a a squirrel had been “zapped”. Since them have caught numerous squirrels this way. You just have to be careful not to put it in a location it might get wet. Also, there is some danger a bird might go in, so I try to hide it somewhat. I have been using it for several years and only caught a bird once (yes I felt bad about it).

    • Thomas Osborne, MD

      Thanks for all the great info.

      Yea, I have 3 macadamia trees and it seems that the iron jawed rodents can sense that the nuts are ripening from miles away. I tried picking a bunch before they ripened.. just so I would win. But it didnt work, they just didnt taste right.

      That is very interesting about the “Rat Zapper.” I have never used one of those. Do you think it could be a fire hazard?

      Thanks!
      T

      • I have several zappers that I have used for years without a problem, but I never thought about a potential fire hazard. Something to keep in mind!
        By the way I am throughly enjoying your website, I have many fruit trees although the stone fruits are doing poorly in the warm winters and the drought. But we are now getting papayas, mangos, bananas, guavas, sapote and dragon fruit. Thankfully the citrus is holding up too.

        • Thomas Osborne, MD

          Awesome
          Thanks.

          Which stone fruit trees are upset? (you can get some with a very low chill factor like the Florida Prince Peach)

          I have had absolutely no success with Papayas but all the others you mentioned are doing great. I think there might be some fungus in the soil that is not agreeing with them (perhaps phytophthora). Any insights on growing papayas is greatly appreciated.

          • All 4 plum trees died, several nectarine and peaches also gone. Of the 5 peach trees I have left, 3 are low chill and still producing fruit, although 2 are not putting on to much new growth. All the plums and peaches have had the twig borer to some degree for many years, but it seems when winters were cooler and wetter (the old normal?) they were healthy otherwise and it did’t seem to bother them much. With the drought, the borer has gone crazy and seems like the trees just gave up. Used to get peach leaf curl too, but have not seen that in several years.
            As for the papayas, we grow the mexican variety. I tried the Hawaiian version, but no luck with those. They did produce, but the fruit was small and not good (that was several years ago tho, so maybe with the climate change I should try again). The mexican papaya trees are growing in the veg garden, which is a sandy loam with lots or organic material from our compost piles over the years. They are watered for about 3-4 minutes, 4 times a day in the summer with mini soaker hose. On top is a couple of inches of eucalyptus mulch. They get fertilizer about once a year if I remember, and need to be replaced after about 6-7 fruiting years. They bear in waves several times a year. Once I counted about 30 on one tree. Some are huge. We give them away, and what we cannot use, I freeze for smoothies.

          • Thomas Osborne, MD

            Thanks Kay
            Sorry to hear about the twig borer.
            Half of my stone fruit have been suddenly hit by a case of gummosis… Which I suspect could in part be caused by injury from a borer type of bug. Why cant they just leave us alone?

            Thanks for the info on your papaya, encouraging to read.
            Ill have to give it a try again.

            Thanks,
            Tom

  11. Central California Gold Country Foothills
    UPDATE- 1 Year Later
    I never followed up using the Dry Ice because even with last falls rain the ground has always remained too dry & cracked for that method to be really effective. Initially I had a little success shooting the ground squirrels by sneaking around outside with a pellet rifle but most of the shots were at too long a range to be really effective. That said with one small change in method I have eliminated all of my resident ground squirrels. We still have a few each day that travel from adjoining lots to feast on “She who must be obeyed”s bird seed & watering dishes. That is frequently a fatal mistake. My new tactic you ask? Just very carefully shoot at close range unseen from inside the house.
    Please note that we live in a rural area in the California foothills where ground squirrels are known plague carriers. I have a small area that is checked several times each day by turkey buzzards so disposal is not an issue. I must add that my Gamo .177 rifle is powerful enough that the pellets easily pass entirely thru so I am not poisoning my buzzards. Estimated 2016 total about 80 so far.
    Russ

    • Thomas Osborne, MD

      Hey Russ
      Thanks for the great update.
      Hopefully we will get some rain in October… But it has been pretty bone dry down here in San Diego too.

      2 days ago I saw a squirrel pillaging my macadamia nut tree after it cleaned a neighboring fruit tree.
      They are really pushing me to the limit.

      Thank you for bring up some great points about hunting safety (both b/c of neighbors and beneficial animals).
      It is easy to get caught up in the moment and loos track of these important factors.

      Thanks,
      Tom

    • Hi Russ,
      What type of pellets are you using (i.e. shape) ?
      Thanks!
      Kay

      • Kay,
        My preference is the Beeman Kodiak Match 10.65 Grain pellet which being heavy shoot very accurately at subsonic speeds and they are quieter. Note that about 1/2 of my shots are directly thru a fiberglass sliding door screen which has little effect at all on accuracy. In the afternoon sun the screen does add a lot of concealment so Sunday I fed three more to the buzzards. I must add that they were covered with flea’s so the plague issue is always a concern.
        Note the Beeman pellets are not available here so I buy them on Amazon and I have to replace that sliding door screen every other year anyway because of my neighbors cat.
        Good Hunting,
        Russ

  12. Hi,

    I have just discovered Rock Squirrels on my property in Salt Lake City and want to get rid of them. I’m not conflicted in the least about killing vermin. Rock Squirrels are huge, about 1.5 – 2 times the size of a tree squirrel. Russ, I’m confused about why you’re shooting from inside the house. Is it to hide from the squirrels or to hide from the neighbors? Do you think the Beeman Kodiak would work on large squirrels? We don’t have a dog or cat–I might poison them and am looking into fumigation. I need to find out when they start hibernating in our area.

    • JB,
      I shoot from inside because I usually get 25-30 foot shots instead of the 50-100 yard shots outside. I do not have to conceal shooting because Tuolumne county doesn’t restrict shooting on residential property and in California Ground Squirrels are considered pests and have no legal protection. I could use anything from a BB to a 50 cal. but the .177 pellet is perfect. There are many restrictions on poison here.
      An online search will that a lot people are using .177 pellet rifles for varmint hunting on animals up to Coyotes. Another search will show that the Beeman Kodiak Match 10.65 will penetrate 7″+ of ballistic gel when shot from a modern springer (Gamo & other) rifle. I want a full penetration shot because I don’t want to give our Buzzards lead poisoning. The Buzzards visit my Squirrel disposal area several times daily so we make a perfect team. Lately the Squirrels have been crawling with fleas and plague is an issue. Either I’m running out of Squirrels or they may be starting to hibernate because I only got three in the past week.
      Good Hunting!

  13. Just wanted to chime in on a device (Underground Exterminator) that connects your car exhaust pipe to a garden hose, allowing you to gas burrowing rodents. It leaves no residual toxins, either in the burrows or in the dead animals. We’ve only had to use it once. Just follow the product directions.

    http://www.undergroundexterm.com

  14. After finishing reading all your articles, I came back to the start and found that you did write an article on squirrels that including trapping information (at least a little). I had unfortunately forgotten that you trapped ground squirrels for a while.

    I apologize for suggesting you let the trapping article slip through the cracks. It was I that let it slip through the cracks in my memory.

    So thank you for all the information you have shared over the years.

    David

    • Thomas Osborne, MD

      Thanks and no prob.
      Thank you for reviewing all the info, and your great feedback. I appreciate it.
      I have lots more info to share, just trying to find some time to dig in.
      Hopefully soon.
      Best,
      Tom

Leave a Reply

Your email address will not be published.

Scroll To Top