The Mole

It is easy to have a love / hate relationship with much of Nature, and it is very easy to define the word “pest” – a pest is an organism that happens to be where we don’t want it to be. This is a great definition, because it leaves plenty of room for that organism to serve a beneficial role in the environment, but excuses our irritation when it shows up in our kitchen, our garden, or the walls of our house. Our principal player for this short article is just such a one of those pests. The Mole. A wonderful and beneficial animal when it stays out of our neatly cared for landscape, but a nasty headache when it decides to use our yard as its foraging territory.

Many people equate moles with gophers, and believe them to be a rodent. However, this is not the case, as the main similarity between these two mammals is that they both live almost their entire lives underground, digging their way through the soil to get from place to place. Moles, in fact, are generally meat eaters, although they do nibble on some tender plant materials from time to time. However, if it weren’t for the unsightly tunnels they make along the surface of the soil – particularly if that tunnel is on our lawn – we’d probably welcome the little guys as serving us some pretty good benefit. You see, moles eat insects, and a great part of their diet is the succulent beetle grubs and cutworms they can find as they tunnel along just under the surface of the soil. Is it their fault that so many tasty treats also pick our lawn for their food?

In addition to insect larvae, moles also feed heavily upon earthworms, so I suppose in this sense they aren’t exactly benefiting our yard, given the great job earthworms do for us in aerating the soil and turning organic matter into usable compost. However, there are plenty of earthworms to go around, and the activity of moles is not going to render earthworms as endangered animals. A five-ounce mole, though, is capable of eating up to 50 lbs. of worms and insects each year.

Moles are tiny little mammals, with elongated, sensitive noses and greatly enlarged front feet, often with huge claws on them. These shovel-like appendages give rise to common names such as the Spade-footed Mole, equating their feet to the tiny shovels that they use them for. In slightly loose soil the mole may be able literally to swim through the soil at a rate of around 16 feet per hour in its surface tunneling and searching for food. These tunnels are usually the evidence you see when you realize moles are in your landscape, but these are not the living quarters for the mole. They will have much deeper, permanent tunnels and chambers that they use for all the processes of living, other than finding food.

Controlling moles can be very difficult. Since they rarely feed on plant materials they are unlikely to accept poison baits that are offered to them, as we do for gophers. So, we have to take other steps in our effort to remove moles from our yard. The first one you should consider, in an Integrated Pest Management approach, is to take back the welcome mat. If it is possible to reduce or eliminate the reason the mole is in your yard then you will have far fewer moles searching in your yard for their food. This means you should try to eliminate the insects that the moles are successfully finding in your lawn or garden, primarily larger insects such as the beetle or moth larvae. If these insects are present they, themselves, are likely causing some damage to your landscape, so eliminating the insects helps resolve two problems for you. Moles are not going to spend a lot of time continuing to search for food in a yard that is providing very little.

Once you have done what you can to reduce the insect populations a second step might be to attempt to repel the moles in some way. One “repelling” device you are bombarded with is the so-called Ultrasonic Repelling Box, that promises to rid your house and yard of all sorts of “vermin”, from cockroaches to rats to mosquitoes and fleas. Outlandish advertising makes it very tempting to spend some money and try these devices, but the fact is that many universities have tested many ultrasonic repelling devices and found them to be, essentially, useless when it comes to keeping any pest animals away. Unfortunately, it just isn’t that simple. You may also see advertising for spinning daisies or vibrating windmills that claim to chase away gophers and moles. It is true that nearby sounds and movement may cause moles to “freeze” for a moment, but they quickly become accustomed to the sounds and begin to ignore it. Experts have noted moles continuing their tunneling within just a few feet of a gas powered lawn mower mowing the lawn above.

There have been many home remedies suggested for repelling moles, and these include pouring household chemicals such as bleach, lye, or ammonia into the tunnels. People have tried flooding, hooking a garden hose to the car exhaust and pumping this into the tunnels, or even offering the moles chewing gum, under the impression that the gum will then clog the innards of the mole. According to university experts in the field of rodent and mole control, none of these alternative measures works in any dependable fashion. And, once again, poison baits can be purchased in stores, but experienced mole control experts will tell you that moles rarely accept such things, as the baits are grain or nut based and moles do not normally feed on these things. In addition, the chance of poisoning your pets is much higher than your success against the mole.

There are some new mole repellent products on the market, though, that do seem to offer some relief. Professional pest management companies that have used these products have reported some excellent results. In the past there were repellent solutions prepared by mixing castor oil and detergent soap, and some university studies found excellent activity in repelling moles, although the effect was fairly short-lived. The treatment lasts for only around one to two months, and if it rains the treatment may need to be redone immediately.

Placing a physical barrier around your property or around critical landscape or garden areas also is a possibility. This will take some work, but you can dig a trench 12 to 18 inches deep, and place a fence of close-meshed hardware cloth or of metal flashing in this trench. The lower edge of this fence should be curved outward at a 90 degree angle, and extend for at least 6 inches horizontally. This will help prevent the mole from simply digging down and under the fence. This type of fence is certainly no guarantee, for moles may still dig into that area from their deeper tunnels, never encountering the fence to begin with.

Professionals who have experience in removing moles from landscape still see trapping as the most effective and reliable method. If the traps are placed correctly the moles should be captured within just a couple of days, quickly and permanently dealing with the damaging animal. The traps themselves can look pretty gruesome, and there are three basic types:

  • Bayonet or harpoon traps – set above the tunnel and spear the mole from above
  • Scissors-jawed traps – grip the mole in strong jaws
  • Choker trap – grip the mole with wires

The traps should be placed over active tunnels, and you can determine this by lightly tamping down the raised dirt of a tunnel for about a one foot length, and inspecting the next morning to see if that area has been raised back up. This would indicate that this surface tunnel may be one the mole is using repeatedly, and it could be a candidate for the trap placement. Experts also have found that the best results are gained from using four or five traps in a single residential setting, not just one. They should be placed carefully in various locations of the mole’s activity, such as near fences, in lawns, gardens, along building foundations or other borders where active runways are more likely to occur. Layers of mulch are often favored by moles, as these areas may harbor the insects they eat, as well as provide a cool, protected layer over them.

Because of the nature of mole traps, not all kinds are even legal in all states, so you may need to determine this prior to planning your control approach. You also should consider contracting with a licensed professional who has experience in this area, and who is familiar with the legal requirements. The best time to trap moles is in the spring prior to their production of litters, or in the fall when they once again are active in their surface runs. Moles are solitary animals except for that time when males and females are in the same burrow system for mating, and for the month or two that the young are still in the nest area with their mother. They do not hibernate, and may be active in either daytime or nighttime and at any time of the year.

One final method for eliminating moles can be provided only by licensed pesticide applicators, and that is the use of a fumigant. The product of choice is a solid fumigant called aluminum phosphide, with trade names such as Phostoxin and Fumitoxin. This is an excellent product for controlling other burrowing animals such as ground squirrels or gophers, but may work only sporadically on moles. The reason for this is the difficulty of finding the moles’ deeper permanent runways, for this is where the pellets of fumigant need to be placed. There are other restrictions on the use of this fumigant, such as the proximity of occupied buildings nearby, but it does offer one more option for eliminating a difficult pest problem.

This fumigant is very different from the “gas cartridges” that you might purchase at a local retail store. Those products produce sulfur fumes that are generally ineffective in controlling moles, often because the mole may quickly produce a wall of soil in a tunnel when it detects the irritating sulfur fumes. The aluminum phosphide fumigant does not elicit this response and can quickly kill the moles if the vapors are released in a runway that can lead throughout the mole’s underground territory.

So, the bottom line on moles is that there often is no pressing reason to kill them, but when their damage to your lawn or landscape is at a level you do not want to tolerate then the use of mole traps will provide the most reliable control.