Of moles and molehills

Eastern mole                                                                         Steve Liptrot/Flickr

Eastern mole                                                                         Steve Liptrot/Flickr

It doesn’t take a crack detective to know that moles are at work — the evidence is underfoot.

Moles are the critters responsible for those long, raised runways in the lawn, the ones your shoes sink into when you walk across the sod. I seem to be having that sinking feeling more frequently and in places where the ground was formerly undisturbed. Moles are on the move, but I’m not sure why.

They excavate surface tunnels, searching for grubs, earthworms and other soil fauna. I would have thought the worms and such would be down lower, in soil that is cooler and damper than the stuff at the surface. But who can fathom the Way of the Mole?

Moles are probably the least understood of our common backyard wildlife. Most people rarely encounter them even though moles are tirelessly at work night and day, satisfying a hunger driven by their hyped-up metabolism. Not rodents at all, these guys belong to an order of insect-eating mammals that also include shrews, another critter known for consuming prodigious amounts of food every day.

Some people get highly indignant about mole "damage," a mostly cosmetic flaw on the face of a pretty lawn. The moles aren't eating plant roots or directly attacking your sod. The little carnivores are actually ridding you of many pests, such as Japanese beetle grubs, which can do serious damage in the yard and garden. And they are aerating your lawn in the process.

In my mind, mole damage is easily dealt with by tamping the runs back down so grass roots don't dangle in the voids below and start to die. I'd rather move on to bigger and better things - dealing with wholesale groundhog raids on the veggies or greedy vole attacks on the flower bulbs.

No, I can't really work up a head of steam about mole issues. Ever hear of someone being attacked by a mole? Or of a mole getting into an attic and chewing on electrical wires, setting fire to the house? C'mon - this is an 8-inch creature with poor eyesight and a strong desire to stay outside, safely underground.

Moles aren't implicated in the spread of rabies like bats, skunks and raccoons, and don't carry hantavirus like some species of mice and rats. I'm more disturbed by the diabolical weapons that mole-hating humans deploy against these innocuous little animals.

Talk about overkill. There are "harpoon traps" set in mole runs that spear their victims with three steel prongs, scissor-jawed traps that cut them in two and choker loop traps that slowly strangle them. People bomb the runs with poison gas cartridges called Giant Destroyers, direct toxic exhaust from their cars into the tunnels or flood them with water.

They pack the runways with broken glass, razor blades, rose branches, lye, moth balls or poison baits with the look and mouth-feel of earthworms. They poke chewing gum down there in the hope it will clog a mole's digestive system, a suburban myth. They install noisemakers, mechanical or electronic.

Most of these methods are useless, a waste of money, detrimental to the environment or hazardous to your own health. I'd like to make a plea for a little forbearance when it comes to the mole. Does it help to think of Mole in "The Wind in the Willows," or to know that the British call them "moldywarpes?"

Mole run and molehill                                    Kim F/Flickr

Mole run and molehill                                    Kim F/Flickr

You are most likely to have the Eastern mole, Scalopus aquaticus, romping beneath your lawn, since that is the most widespread species from the Atlantic to the foothills of the Rockies and from southern Canada to the Florida panhandle. The star-nosed mole is found here, too, but is strictly a critter of low wetland areas with damp soil. (With a snout of 22 fleshy tentacles where its nose should be, it has a face only another mole could love.)

Moles use their broad, powerful forepaws to "swim" through the soil, excavating tunnels at the rate of 18 feet per hour. If the tunnels prove productive, they scurry through them picking off prey, moving at a brisk 80 feet per minute.

Mole fur has no nap but rather sticks straight up so moles can move backward or forward without friction. You can't rub a mole the wrong way. Moles also have twice as much hemoglobin in their red blood cells, to cope with the low-oxygen environment found underground. In their dens, which sit a foot or more deeper than the surface feeding runs, they raise a single litter of young in the spring.

Moles otherwise lead a mostly solitary life, there in the dark netherworld. They are fastidious eaters, pulling earthworms through their tightly clasped paws to force dirt and debris from the worm's gut before chowing down. They have a pretty tough life - why else would the collective noun for a group of them be a "labor" of moles?

You may have heard you can rid yourself of moles by killing off their food supply. That may not be a practical approach, since a good part of their diet consists of earthworms, which you want to have around.

I can't recommend drenching soil with pesticides that will kill off all soil fauna, and the biological control known as milky spore is no panacea. This fungus, promoted as a "cure" for Japanese beetle grubs, doesn't survive all that well in cold climates and takes years to become effective. Plus, there are nearly a dozen other grubs inhabiting sod that laugh at milky spore.

If moles are creating havoc in the garden (as opposed to the lawn) you can always install a barrier fence of tightly-woven wire sunk 18 to 24 inches into the ground. You can also try the newer repellents formulated from castor oil, although the effectiveness of these is not well-established and, in any event, is temporary.

You are unlikely to have lots of moles unless you live near woods or meadows where their food is plentiful. I've read that the average suburban acre can only support two to three moles, so most mole warriors aren't facing an army of crafty little critters. This is not "Caddyshack."

Really - cut the moles some slack and direct your animus toward more serious threats. If bomb-wielding terrorists don't get you going, tomato-eating squirrels just might. Don’t make a mountain out of a molehill.