Question
Dear Stephhen,
I am sure you must have heard about this problem a lot.
Our back yard (since last year) and now also our front yard feels like a big grass/soil sponge. We have some animals (never seen them) digging tunnels underneath the lawn and also even under the house. I would love to "outvite" those little gritters to go somewhere else (there is a huge field behind our block and it/they would not be bothered by anyone or anything and vise versa).
I heard on a radio show that sprinkling the area with caster oil would work. I tried it on our front yard, but all the tunnels reappeared along with new ones. Would you know any "humane" trick to rid of those unwanted lawn airators?
Thanks so much.  Martina

Answer
I have written a great deal on controlling moles below. I provide it for your inspection, even though you noted that you wanted a different kind of solution.  Unfortunately, there is no so-called humane solution for mole control other than Mole med which is a castor based product. Some people do get relief by controlling grubs but only if there aren't enough worms in the soil to sustain the moles. The reason I question the humaneness of repellents is because if they work (which is often not as well as people would like) then you in effect force the animal to less preferred land. It is like pushing your pet from the food dish to the garbage can. I don't think that is really humane. It may be less hurtful but humane? Any way, there is no magic in controlling wildlife.  I have a lot of information below. At the very least it will save you from wasting money on other so called effective humane techniques. Sorry.  

Getting rid of moles

Before anything make sure the problem you are complaining of is moles and not pocket gophers or voles. If the latter two visit http://icwdm.org/wildlife/mole.asp . Moles eat insects and worms. Their damage to plants is inadvertent and only occurs if they separate the roots of the plant from the surrounding soil. They don't eat plants. However, voles eat plants and will work above and below ground. Voles don't make soil mounds but can dig small dime sized holes that disappear under the soil (this is true of the Pine Vole). Pocket gophers eat plants and make numerous boils on the surface of the ground and live primarily in the Midwest to the west in N. America. Moles are twice the size of mice and rarely if ever come to the surface. Voles are the size of mice. Voles will use a tunnel dug by a mole. Make sure you know what the problem is. By the way, if you have moles you don't have many of them. On average, you will have 3 moles per acre. But remember they can dig 100 feet per day depending on soil conditions.

First, don't bother with chewing gum, thumpers, sonic devices mothballs etc. There is little to no concrete evidence that they work. Gas bombs tend not to work because the tunnels are too long and the moles are too fast. It is like trying to push smoke through a 30 foot straw, very hard (mole tunnel networks are much larger than 30 feet). People who think they work often don't know that during dry periods moles move deep into the soil so they won't provide visible damage until rain or watering of the lawn. If you aren't sure if the tunnels are still being used, roll down the tunnels and wait to see if they reappear. The piles of dirt are indicative of deep tunnels as opposed to surface tunnels. You need to trap these with scissor traps or No-mole traps next spring after the ground softens. Surface tunnels can be trapped with harpoon, scissor, Nash traps or Nomol. Traps can be obtained at  various vendors. Again you can find them at http://icwdm.org . Some people suggest that pets be used to control moles, I have my doubts. Certainly cats and dogs kill some but I question they would ever be efficient enough to satisfy the landowner.
There is a new pesticide on the market called Kaput but there are questions concerning its efficacy. By that it is meant that some would like to see dead moles autopsied to determine if they were killed by the poison. The only registered repellent on the market is called Mole-Med It essentially uses Castor bean oil to allegedly drive the mole away. The evidence for this product is also debated.  I don't know if castor oil kills worms which are the primary food source for moles. There is no scientific evidence that any plant, chewing gum or thumping device will keep moles away.  Talpirid by Bell Labs is another story. You will most likely need a pesticide applicators license to use but early research seems promising.

Nevertheless, I am a firm believer in trapping.  2. Use proper equipment such as harpoon, Nash or scissors traps or Nomol?traps. Traps cause minimal damage to your lawn and certainly not as much as a mole will. Nevertheless if you are worried about the traps damaging your lawn use harpoon traps. All the damage they do is poke holes into the grass. Nomol traps are the safest if you worry about pets etc. Third, get proper training, visit http://icwdm.org .  Many people mistakenly think that trapping is not effective because they tried it and it didn't work. What those cynics need to realize is that the trap is only as good as the trapper who uses it. Training and proper instruction is critical to success. Learn mole biology. The primary diet for moles is NOT grubs (although moles eat them, grubs are not their primary food. Their primary diet is earthworms. So even if you get rid of grubs you may still have moles who are seeking worms. Can removal of grubs work? Yes if you don't have enough worms to justify the mole's digging. However, I have heard that grubs are becoming resistant to some of the pesticides and/or that homeowners are not following the directions of the poison.  You can see my bias against unnecessary poisons. If you choose to use poisons contact your local garden supply. They should know what is effective in your area. The beauty of trapping is that it works, is safe and is poison free. As for prevention, the only thing guaranteed to work is to pave your lawn which is certainly not cost effective or environmentally sound. Finally, make sure trapping is legal in your state. Unfortunately, states like Washington and Massachusetts have listened to animal rights protest industry groups and banned mole trapping through the ballot box.


Disclaimer: As with any activity, remember that animal damage control comes with its own risks and problems which can include but are not limited to legalities, health threats, and personal liabilities. Be sure to follow all state laws governing wildlife and make sure you have a thorough understanding on how to resolve the animal damage complaint. My advice is only as good as your understanding of me and my understanding of your situation. If you have any questions be sure to write back.