Those moles are everywhere!

You would never imagine that mole activity could be so rampant during the winter months in Missouri. However, such is the case this year with mild winter conditions keeping the ground in a thawed state during much of the late fall and winter. Moist conditions early draw earthworms to the surface with their predators not far behind. Mole runs were appearing in November, December and January! Drier conditions as of late have reduced some of this mole activity, but not for long as spring rains are right around the corner. We have simply had an unbelievable winter for excessive mole activity.

While most people have never seen a mole, they are well aware of the damage they cause to lawns and flower beds. Most individuals think moles feed primarily on the roots of plants and cause them to die. In truth, mole 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.

Animal foods constitute about 85 percent of a mole’s diet. This primarily includes earthworms (their main source of water) and white grubs; however, millipedes, centipedes, spiders, sow bugs, snails and slugs are eaten in considerable amounts. Moles are insatiable eaters and can consume 70 to 80 percent of their body weight daily.

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 one foot per minute. They tend to feed and rest on twohour cycles, 24 hours a day.

Management or Control
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, with a small stick or broom handle, poke holes in various runways over the entire network. Come back two hours later and inspect those holes. Find the tunnels with the holes plugged back up and this indicates to you which runways are active feeding tunnels at that time. These are the tunnels that you want to set your traps on. The key to successful trapping is to locate the active runways.

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 the MU Turfgrass Research Center. There are products (repellents and bait) on the market that are available to homeowners and can be purchased at local nurseries or garden centers.

Several products based on castor bean oil as the active ingredient tend to work as a repellent. 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 repellent-type products are marketed as natural and safe, but information about effectiveness is mixed.

More recent products include several baits that seem to be very effective if applied properly to active feeding runways. 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 before placing the bait. They are both packaged in syringetype applicators with which the bait is injected into the tunnels. Both claim 98 percent effectiveness.

The latest mole bait registered is "Talpirid" (Bell Laboratories), a bromethalin-based product that actually look’s, 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 or 20 worms.

Many individuals think that all they need to do to control moles is to control white grubs. While this appears to be true, it is the control of an off-target organism that reduces mole activity. The application of soil insecticides for controlling grubs will also control earthworms to some degree, sometimes causing moles to move out. Controlling earthworms is not recommended since they are considered a beneficial organism that aerates the soil and breaks down organic materials. This approach to mole control can present hazards to the environment and can be quite expensive. There are no pesticides registered for killing beneficial earthworms.

Additional information on moles can be found in MU Guide #9440, "Controlling Nuisance Moles." The descriptive information on moles was found in "The Wild Mammals of Missouri" by Charles W. Schwartz and Elizabeth R. Schwartz.

Remember
All rodenticides are designed to kill mammals. Take all reasonable precautions to prevent exposure to humans, pets, and non-target mammals, birds and fish.

Recommendations for the use of agricultural chemicals are included in this publication as a convenience to the reader. Any mention or listing of commercial products or services in this publication does not imply endorsement by University Outreach and Extension nor discrimination against similar products not mentioned. Individuals who use agricultural chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage regulations and examine current product labels before applying any chemical. For assistance, contact your University Outreach and Extension Center.

Brad S. Fresenburg
Extension/Research Associate
University of Missouri Turfgrass Research