Dealing With Those Pesky Moles

Published: April 1, 2010

Moles have been very active over the past two years. Activity in the late fall and early winter months is not uncommon as many areas are heaved by feeding runways and mounds. If you consider the excess rainfall we have experienced these past two years, it is easy to understand why mole activity has increased. Saturated soil conditions force their primary food source to the surface and therefore greater mole activity is evident.

While most people have never seen a mole, they are well aware of the damage they cause to lawns and flowerbeds. Most individuals think moles feed primarily on the roots of plants and cause them to die. The truth is, moles’ feeding on plant material is very limited. It’s the air pockets they create around roots and flower bulbs that cause them to dry out and die. Others will swear by a number of home remedies to control or repel moles. These include such things as human hair, Juicy Fruit gum, poison peanuts, mothballs, flooding tunnels with a garden hose and water (flooding tunnels creates a moist environment favorable for earthworms), a hose connected to a cars exhaust and finally, pets (some dogs and/or cats can be effective).

Moles live most of their life underground and are highly specialized animals for their subterranean way of life. The Eastern Mole is a small, sturdy animal, 5 ½ to 8 inches long, with a somewhat cylindrical body and elongated head. The Eastern Mole is grayish-brown on the back to pale or more brown on the belly. Their velvety fur often has a silvery sheen. Occasionally bright orange or cinnamon-yellow marking will occur. Their fleshy snout serves as a highly sensitive organ of touch and smell to seek out numerous food sources. Their tiny eyes are concealed in fur and covered by fused eyelids; sight is limited to distinguishing light from dark. The greatly enlarged front feet are normally held with the soles vertical and pointing outward. They possess well-developed claws that have a specialized bone attached to the wrist, which aids in digging.

Moles construct networks of tunnels in the soil surface. Many of these are built after rains when the mole is in search of new sources of food and are usually not re-used. Digging of surface tunnels normally proceeds at a rate of 1 foot per minute. They tend to feed and rest on two-hour cycles, 24 hours a day. Animal foods constitute about 85 percent of their diet. This includes earthworms (their main source of water) and grubs, primarily; however millipedes, centipedes, spiders, sow bugs, snails and slugs are taken in considerable amounts. Moles are insatiable eaters and can consume 70 to 80 percent of their body weight daily. Moles generally move up or down within the soil profile to follow food sources such as earthworms, which move with soil moisture.

Moles also create mounds (called molehills) of soil in the lawn by pushing up soil developing deeper, permanent tunnels and nesting cavities. Mating occurs in the spring with a single annual litter of 2 to 5 young being produced in March, April or the first week of May. High infestations consist of 2 to 3 moles per acre.

Management or Control:

There are products on the market that are available to homeowners and can be purchased at local nurseries or garden centers.

Most products tend to work as a repellant based on castor bean oil as the active ingredient. Many have been tested on the Eastern mole and appear effective on that species, which is our predominant species. These products need to be sprayed (garden hose-end applicator) or granule applied (through a spreader) at regular intervals to maintain a barrier that repels these small mammals to your neighbor. The repellant type products are marketed as natural and safe, but information about effectiveness is mixed. Mole-Med may have changed its name to Chase due to new ownership and is available in both liquid and granular form. Other repellants include Scoot Mole, Shotgun Mole & Gopher Repellant, Mole Max, Mole-Out, Whole Control, Schultz Garden Safe Mole Repellant, and many others. All are based on some percentage of caster bean oil as the active ingredient. Formulations vary with each, sprayable or granular. These products will generally treat 5,000 to 10,000 square feet and last one to three months. Many of the ready-to-use products are costing around $15 to $20 per item.

More recent products include several baits that seem to be very effective if applied properly to active feeding runways. See below on how to locate active feeding runways. Wear rubber gloves whenever handling and placing baits in tunnels.

Two products called “Kaput Mole Control” (Lesco) and “Moletox Baited Gel” (Bonide) are water-based gels containing warfarin (0.025%) as the active ingredient and flavored like their primary food, earthworms. It is best to locate the active runways as you would for trapping (see below) before placement of the bait. They are both packaged in syringe-type applicators with which the bait is injected into the tunnels. Usually figure around $20 per syringe.

The latest mole bait registered is “Talpirid” (Bell Laboratories), a bromethalin-based product that actually looks, feels and tastes (so they say) like earthworms. Each worm contains a lethal dose of bromethalin. It is the only mole bait that has submitted efficacy studies to EPA.

This product appears to be a higher cost item at around $50 per box for 20 worms.

MOTOMCO Mole Killer is a bait similar to Talpirid, but in a more affordable package of eight worms for around $18 to $22. Gemplers, QC Supply and MFA are carrying this product.

We can also find some poisonous granular baits of a different class as compared to the previous baits mentioned. These include “Moletox II” and “Mole-Nots”, both of which are cracked corn baits laced with 2% zinc phosphide. One teaspoon of material will treat an active tunnel. While some results indicate excellent control with these products, keep in mind that moles do not prefer grains in their diet.

Another granular bait is “Mole Patrol Bait.” Mole Patrol is a ready-to-use, pelletized bait highly palatable with unique attractants. This product contains chlorophacinone, a historically sound anticoagulant of the rodenticide industry. Some studies indicate 100% control of moles. A one-pound container can be purchased for less than $10.

Trapping is still one of the most efficient means of controlling moles and anyone can be successful by following a few simple steps. If you have the network of shallow runways used for feeding, then you can do some effective trapping. First, you need to locate active feeding runways. Second, select a tunnel to set your trap. There are several types of traps to choose from and simply follow the instructions of the manufacturer to set the trap. The Nash trap (wire hoop type) and the Victor “Out O’ Sight” trap (scissors type) do work, but seem to be more difficult to set. The Victor “Harpoon or Gig” type trap - has been the most successful trap for us at the MU Turfgrass Research Center. However, a newer trap called the “Easy Set” mole eliminator (scissor type) is by far the easiest trap to set. Even individuals who have difficulty setting the heavy spring type traps mentioned above can set this trap by simply stepping on the trap with body weight. This trap is more expensive ($32), but well worth it. All traps can be found at garden centers, hardware stores or found online (Gempler’s, Forestry Suppliers, etc.).

Identifying Active Feeding Runways:

First, with a small stick or broom handle, poke holes in various runways over the entire network. Come back two to three hours later and inspect those holes. Find the tunnels with the holes plugged back up. This will indicate to you which runways are active feeding tunnels at that time. These are the tunnels that you want to set your traps on or place baits in.

Controlling and trapping moles requires a little time and patience. Your success with controlling moles is dependent on locating active runways and the proper placement of a trap. Additional information on moles can be found in MU Guide #9440, “Controlling Nuisance Moles.”