Turf - Understanding Moles

Moles and mole damage is often not well understood by turf managers. The following is a short article on these pests.

Moles belong to the group of mammals that are insect eaters. They are often incorrectly called "rodents," the group or family of animals such as mice, rats, and squirrels. There are different species of moles in the United States. However, the common mole is the most widespread in the East and is the most likely mole encountered in Delaware.

Description and Habits

Moles have short, velvet-like fur that varies in color from gray to brown. A fully grown mole is 4 to 6 1/2 inches long, not including its short tail. Adults weigh 3 to 5 ounces. The eastern mole has a long naked snout with nostrils that open upward. Moles have a voracious appetite and can eat 70-100 percent of their weight daily. They feed while burrowing just below the surface of the ground where their preferred foods, including insect grubs, adult insects, and earthworms, are abundant. Plant parts are eaten only occasionally.

Moles live alone, but burrow systems of several moles may connect. Burrowing occurs year-round, peaking during warm wet months. When making feeding tunnels near the surface, moles may burrow up to one foot per minute. A single mole can create an extensive network of burrows. Moles tend to burrow along structures, fence lines and walkways. Therefore, one animal can be responsible for considerable damage to a lawn or garden.

Breeding takes place in February and March; young are born 42 days later. Females produce one litter of four or five young per year. Young are independent of their mother at one month and reach sexual maturity in one year.

Moles live underground and seldom venture out of their burrows. They are most active early in the morning and late in the evening. The ridges produced by their burrowing plainly indicate their presence. Most of the tunneling is done in a random search for food, so many of the tunnels are seldom re-used. This is important to remember when trapping moles. Their more permanent or "active" tunnels usually run along fences, borders or other protected places that lead to feeding areas.

Moles feed almost exclusively on soil insects -- earthworms and grubs are the most important food sources. Because they eat insect pests, they can be beneficial. A mole has a tremendous appetite and can consume nearly half its own weight in food daily. Roots, bulbs and tubers of plants are not target food sources, but may be damaged indirectly as moles dig through the ground in search of grubs and earthworms. Plant parts may subsequently be eaten by mice, which use mole tunnels for protection and as avenues to food supplies.

Information from the UD Extension Fact Sheet HYG-61 and the University of Nebraska Extension Factsheet on "Moles and Their Control"