Each spring as the weather warms and planting time approaches, a proliferation of molehills are seen in the Pacific Northwest. Elimination of nature's little rototillers is virtually impossible so why do we continue these desperate efforts to do him in? If you own a golf course or an acre of manicured lawn, the answer to that one is obvious!
Many and varied are the fairy tale approaches to dealing with the elusive mole. Be advised that only one - trapping - has proven reliable. Before continuing this chronicle of mythical mole management, let's consider the physique and eating habits of our subject.
The mole's snout is long and slender and admirably suited to assimilating a diet consisting primarily of earthworms with an occasional side dish of grubs or larvae. The muscular forearms and extremely large forefeet enable this critter to "swim" through the dirt at a remarkable pace. His habitat is a lengthy network of runways through which he continually roams in search of food. Keeping these fact is mind, let's get on with the most common mole fighting misconceptions.
POISON FUMES - Specifically mole "bombs". With those great big feet, your mole has probably burrowed out of range at the first unsavory whiff. Fumigating your soil with poison gas has a tendency to kill the good bugs and bacteria that assist you in your gardening. Fumigants MAY occasionally kill a mole or at least drive him away, but not consistently. Some people try to use car exhaust, which is usually not effective and, technically, illegal. Fumigants are most likely to work in heavy soil that is saturated by water.
MOLE BAITS - There are some interesting "moleicides" now available for managing moles. In the past, all mole baits were hard pelletized formulations - unlikely materials for an animal that lives on soft, juicy earthworms. Within the last few years, a couple of gel-baits ("Moletox Gel", "Kaput") have been registered that may be effective and the latest things (2004) are mole baits ("Talpirid", "Motomco Mole Killer" & "Tomcat Mole Killer") that actually look, feel and taste (so they say) like earthworms. As of 2011, we have not seen control with any of the mole baits we have used in our limited tests.
CHEWING GUM - With such narrow mouth parts, the mole probably isn't capable of biting into a piece of gum, no matter how badly we'd like him to "gum up " his interior. In our tests, moles ignored chewing gum. Tecnically, using any unregistered material as a rodenticide (no matter how benign) is not legal.
CHOCOLATE COVERED LAXATIVES - As with the gum...moles don't eat this and it is not legal to use it as a rodenticide.
NOXIOUS SUBSTANCES IN THE RUNS - Occasionally something as strong as mothballs or "drain cleaner" placed in tunnels will move your mole next door temporarily, but he'll probably be back. As mentioned above, it is illegal (and sometimes dangerous) to apply non-registered materials as pesticides. Environmentally speaking, it's a very unsound practice. If you want to try chasing your mole away, stick to commercial mole repellents.
THE SHOTGUN APPROACH - Never handle firearms unless you have been trained in their safe use! Although this method works, it's illegal to discharge firearms in many areas. However, you can often kill or stun a working mole by slamming a heavy shovel down on the growing mound or ridge.
WATER TREATMENT - By the time you've flooded the runways with the garden hose, your mole has probably moved to higher ground and built and furnished new quarters. This method occasionally works if you have a heavy soil and use lots of water from several hoses at once. Some folks have effectively used several buckets of water all dumped at once into the runs. Be aware that some folks have ended up with flooded basements using this method.
VIBRATING WINDMILLS AND ELECTRONIC DEVICES- Perhaps, if you happen to place one directly over his nest, you may move your mole a couple feet to one side - but, don't count on it. In controlled tests, none of the electronic repellers have been effective.
HUMAN HAIR - As a repellent it's right up there with the ineffective mole plant Euphorbia lathris which, incidentally , is harder to get rid of than the mole, once it is established.
Moles rarely, if ever, eat bulbs or vegetables or ornamentals. Squirrels and tunneling voles wreak havoc here. No one will deny that moles can drive you crazy with their volcano-like hills and raised feeding runs but much of what's said about them isn't true.
A cat or dog that is a good hunter can do an excellent job of keeping the mole population in check. The only other sure method is trapping. The right trap is essential. Unfortunately, all of the effective mole traps were outlawed for general use in the Washington State 2000 elections (effective Dec. 7, 2000). Analysis of Initiative 713 by the Attorney General's office has concluded (June 2002) that any trap (other than "common rat and mouse traps") that holds, pierces, grasps or pinches a body part in any way is included in the ban. One can still legally purchase these traps but may not use them for capturing animals. The revised RCW (77.15.92 & 77.15.94) can be seen HERE. (Note subsection (3))The Attorney General's analysis can be found at http://www.atg.wa.gov/opinion.aspx?section=archive&id=7974
If you and your moles are truly incompatible and you must get the little beasts off your property, consider trying some of the non-trapping methods listed in "Principles of Vertebrate Pest Management" ( http://snohomish.wsu.edu/garden/vertchap.htm#Moles) but only where they're really causing damage. Let the wild areas remain a refuge for these incredibly well adapted creatures.Additional information - Moles - WSU publication EB1028. (Being updated 01/07).
For more information contact your WSU Extension office.