As in any pest control program, it is crucial that the homeowner understands the habits of moles before attempting to prevent them from damaging his lawn. In a July 2002 University of Missouri Extension publication, fish and wildlife specialist Robert Pierce writes, "The ridges of their tunnels make lawn mowing difficult. Since the roots are disturbed, grass may turn brown and unsightly ... plants may be physically disturbed as moles tunnel in search of animal organisms in the soil."
Moles tend to prefer moist, sandy soils. Lawns with these features are simply easier for the rodents to crawl through. Keep irrigation to a minimum, and periodically pack the turf down with a sod roller. But such practices may create unfavorable conditions for the lawn.
Ridding a yard of the mole's favorite meal will not only discourage its activity but also strengthen the turf at the same time. According to Pierce, moles eat all kinds of insects, but "earthworms and white grubs are preferred foods." White grubs feed on grass roots and can eventually kill sod by separating if from the soil. If you suspect a grub infestation, apply an insecticide per label instructions in the spring and fall. But often, a mole may do additional damage to an insect-free lawn while searching harder for food.
Traps and Baits
In an April 2006 Michigan State University Landscape Alert newsletter, crop and soil sciences expert Kevin Frank writes, "The only time tested effective method for controlling moles is a good trap." Most experts seem to agree, but trapping moles takes practice. Normally, the hunter must get to know his intruder's tunneling frequencies before understanding where to place the traps--the more, the better.
A bait called Talpirid is available for $35 to $45 per 20 pieces. It looks like a fake fishing worm. Place it in the mole tunnel and hope the critter eats it and dies.