Mole control

Oct. 8—Are you finding that your yard is being destroyed by some mound building creature?

It more than likely is a mole, especially if you can see his tunnels running along the surface of the ground. While some of the techniques that homeowners are using to control moles are rather innovative, others are quite dangerous. Some of the methods such as "chewed" bubble gum, fox urine powder, electronic devices that produce vibrations underground, plastic owls, and windmills, and the ever popular and most dangerous, the propane hose in the tunnel.

Some other often suggested remedies that can be unsafe and should be strongly discouraged are the use of broken glass and engine oil. There are also several other products available, which include chemicals that target either the moles or their food source. While many people claim to have experienced good control from the above methods, others state that such remedies failed to remedy their problem.

In order to understand why certain controls are ineffective, it is important to know more about mole biology. Little information exists in this area. Two main reasons for this are that moles do not live well in captivity while being studied and are hard to observe in nature because of their underground habitat.

What we do know is that moles are from the family Talpidae?

In North America, there are six moles of which the eastern mole (a.k.a. common or grey mole) is the most prevalent. All moles live in underground burrows with volcanic shaped plow-outs, have large broad feet, and are solitary animals. Moles are insectivores and seem to prefer earthworms when available but will eat grubs and other insects. They almost always pick up their food and orient it to be eaten headfirst. Their nose and tail have special nerve endings which can strongly sense vibrations. These vibration sensors and scent allow the moles to detect earthworms and grubs crawling several feet away in solid dirt.

Moles very rarely consume plants or plant parts. Damage of this nature can often be attributed to voles, white-footed mice, and house mice that use mole tunnels. A mole will consume 70-100% of their body weight of insects per day. In addition, moles have an extremely high metabolism and complete digestion takes only 90 minutes. Moles can dig at about 18 feet per hour and can move through existing tunnels at about 80 feet per minute. Moles contain twice as much blood and red hemoglobin as other mammals of similar size, allowing them to breathe easily in an underground environment of low oxygen and high carbon dioxide. Moles are territorial and will not voluntarily leave a productive feeding area.

There are a few methods available with proven results. Chemical controls of the moles' food source have been shown to be somewhat effective. This is the use of products like imidacloprid (Merit) and halofenozide (GrubX or Mach 2). Both products are long lasting but must be applied as preventative treatments, before the grubs hatch. After hatching, trichlorfon (Dylox) and carbaryl (Sevin) formulations are available. Problems that exist with this method are that most of these chemicals pose no threat to earthworms so the moles will continue to have an available food source.

Trapping is one of the most reliable methods of mole control. There are several traps available. The key to trapping moles is patience and persistence. Trapping can be done at any time of the year, but some people suggest that spring, while females are pregnant, and fall, before moles move to deeper tunnels, might be the best times. Mole traps work because moles usually try to reopen a blocked tunnel. As the mole clears the tunnel, it pushes up on the trigger pan, releasing a spring and is either captured or crushed by the trap. Two traps should be placed in a run with each facing opposite directions in the tunnel, so that it will trap the mole from either direction of travel.

A new product called Talpirid is now available and boasts the claim to being the only product submitted to the EPA with "laboratory efficacy tests" on moles. The product is designed to resemble an earthworm and is anatomically correct, with a scent similar to that of the natural food source. The active ingredient is Bromethalin, which is a fast-acting chemical that works in the fast digestive track of the moles. A homeowner with a problem should start by using one of these three methods before wasting valuable time and money on ineffective home remedies.

For more information about moles, you can contact your ag educator at your local OSU Extension office.