Published: May 14, 2008 02:13 pm            

Mole control: Buyer beware

Moles are back at it again. These small subterranean tunnel-making pests can cause big frustrations for those managing turfgrass and landscapes. Mole damage is most noticeable during the spring and fall, but spring may be the most effective time to control them, according to Tim Gibb, a turfgrass specialist at Purdue University.

Moles are gray, furry mammals that reach six to eight inches in length. They have abnormally high metabolism rates, which means that they must constantly eat. They are active almost year-round, day and night.

Moles are unique animals and are perfectly adapted for their underground life, Gibb said. They are nearly blind and have very strong front feet designed for tunneling. They can tunnel as much as 100 feet per day in their quest for food. Frozen soils during the wintertime force moles to tunnel very deep underground. Evidence of this wintertime activity are large piles of black soil deposited on top of the lawn or garden.

Moles mostly feed on earthworms. While they do eat grubs, it’s an old wives tale that grubs are the reason that moles are in a lawn. Therefore using grub control products as a method of controlling moles will not be effective. Even in grub free lawns, moles continue to survive, because the majority of their diet consists of the ever-present earthworm.

Moles are not rodents like rats and mice, which can be baited using rodent foods. Poison peanuts or other grain baits won’t work since moles don’t feed on seeds, alfalfa pellets or any of the typical baits that are sold to “kill rodents” even though some are touted as a control for rodents and moles.

People also should beware of false claims about schemes to drive moles away. Many books and magazines have references or advertising concerning bizarre strategies to control moles. These include putting mothballs, human hair, razor blades, or chewing gum in their tunnels, or using pinwheels or ultrasonic devices to scare moles away. These just do not work.

The only two methods of effectively controlling moles are: (1) to use a bait to which they are attracted or (2) to physically remove them.

A fairly recent bait that has been proven to be effective is packaged and sold in the form of a worm. The attractive smell and taste that is incorporated into the worm, together with Bromethalin (the active ingredient that poisons the mole), makes for a lethal combination.

Two effective mole traps can be used depending upon where the moles are working. A scissors trap is better for use in subsurface, or deep, mole runs. A harpoon trap is usually easier to use when the tunnels are near the surface.

Whether using traps or worm-shaped baits, placement is critical. Choose a run that the mole uses regularly. Usually this is a run that is in a straight line as opposed to squiggly tunnels that are generally used for food foraging only. The best straight runs follow a structural guideline such as a curb or a gutter, because these are used regularly as the moles travel from their nest to the foraging area. To determine if a run is active, stomp it down flat then check the following day to see if it is pushed back up. If the tunnel has been repaired, it is usually an active tunnel and should be considered for trapping or baiting.

Mole traps and baits are available at most hardware, home repair and farm supply stores, generally right there in the middle of a bunch of mole control products that do not work. Buyer beware.

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Purdue-USDA Wildlife Conflicts Hotline: (800) 893-4116; www.wildlifehotline.info

— Doug Akers, an Extension Educator at the Boone County Cooperative Extension office, may be reached at (765) 482-0750 or dakers@purdue.edu.

        

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