By Beverly Adams, Forsyth County Extension
Here at the Extension office I get lots of calls this time of year from clients who have something damaging their lawns, leaving mounds of dirt from digging. The answer could be several things.
To help narrow it down homeowners can look for clues, like the size of the holes, and where they are located. To determine exactly what is causing the damage you might set up a trail camera and catch the animal in the act.
Most of the time the smaller four-legged excavators are in the rodent family. If the damage is more extensive it could be a larger mammal such as an armadillo.
The rodent family includes dozens of possibilities for Georgia, but I want to talk about moles. Moles are insect eaters and are closely related to bats and shrews. In the fall, white grubs are hatching near the soil surface so there is a lot more mole activity. White grubs are common in lawns and are usually larvae of Japanese beetles or other beetles that have laid their eggs this past summer.
The grubs feed on the roots of grass and can occasionally cause damage to a lawn. Moles tunneling under the lawn can be a symptom of a grub problem, especially in yards that are consistently irrigated.
If white grubs are found to be a problem in the lawn (around 10-20 per square foot of sod), then insecticide treatments are justified to avoid root damage from the grubs. Early fall is the best time to treat for grubs. Treating for grubs may temporarily reduce this food source for the moles, but it can increase their digging activity in search of food.
Because moles eat insects, grubs and worms, there is no good way to bait them into a trap and poison baits are seldom effective. Moles live and travel in underground tunnels just below the soil surface.
Generally, only one mole lives in each burrow. However, you may have a network of underground runways that house individual moles. Most mole burrows average about 5 to 8 inches beneath the surface. Packing the soil with a roller or reducing soil moisture from frequent irrigation may reduce a lawn’s attractiveness to moles. Packing may even kill moles if done early in the morning or late evening when they are most active.
No chemical products have been shown to be effective at repelling moles. Fumigants containing aluminum phosphide or gas cartridges are labeled for controlling moles, however, exact placement of fumigants in the mole’s deeper burrows is required to be effective.
Home remedies have not been proven effective at controlling moles. Trapping is the most effective and practical method of getting rid of moles. There are several mole traps on the market that are specifically designed for killing moles with spring-loaded mechanisms. The traps should be placed in straight runways that show fresh signs of mole activity. Take care not to disturb any part of the mole’s runway tunnel except where the trap is being inserted.
Another option is to bury a large coffee can or wide-mouth jar in the mole’s tunnel to create a pit trap and cover the top of the burrow with a board. The moles will fall into the pit trap and be captured alive using this method.
For more information on trapping techniques used for moles and other pests, see the Internet Center for Wildlife Damage Management website at icwdm.org/species.
Beverly Adams is the Agriculture and Natural Resources program assistant for the UGA Extension Forsyth County.