“Fee, fie, fo, fum. I see the dirt from some furry bum.” Many have walked into the yard and found perplexing piles of soil in their lawn or flower beds. They want to know what critter made the heap and are worried that it means something worse is going wrong. There are several animals that are common yard visitors. Keep in mind that the usual motivation for digging up yards comes down to two things: food and lodging. The time of the year makes a difference in the frequency of digging. Often, more damage occurs in the fall and spring. Michigan State University Extension hotlines receive many calls at certain times of the year about mystery mounds.
In the fall, animals are trying to pick up as many calories as possible to make it through the winter. The fatter they are, the better chance they have of living long and prospering. In the spring, these same animals are trying to regain weight, especially if there has been a great deal of snow cover or extremely cold weather. Food hunting is “job one.” It is possible to identify the digger by the clues left at the scene of the crime. Let’s look at the three main suspects.
Shallow holes in the ground, surrounded by a ring of loosened soil
Skunks are often the cause of these clues. The soil disruption happens overnight because skunks are nocturnal feeders. The hole is approximately the size of a skunk nose. The skunk presses its nose to the soil and digs with its long, front claws. Skunky knows that just below the surface is a protein-rich treat, just waiting to be harvested. There can be so many holes that they coalesce into an area the looks like it has been tilled.
In the fall and all during the growing season, skunks are on the patrol for earthworms, grubs and a variety of soil insects. Their diets also include crayfish, small animals, birds and their eggs, frogs and turtle eggs – if they can find them. Skunks enjoy a diet that extends into fallen fruit like mulberries, raspberries, cherries and grapes. They don’t jump and cannot climb to any extent, so they work close to the ground.
Chunks of sod that have been ripped up and flipped over
Raccoons enjoy diets that are almost identical to skunks, but raccoons use their front paws like hands. They will pull and flip pieces of sod. This behavior is quite common on newly laid sod or grass with shallow roots. Ripping and tearing is easier. Since skunks and raccoons can be feeding during the night in the same area, you may wake to a powerful skunk odor. The gentle skunk is being harassed by the backyard bully raccoon.
Mounds of loose soil on the lawn
Moles leave piles of soil on the surface because they are pushing them up from below. There are no visible holes. In warm weather, the star-nosed mole works about 6 inches or more below the surface and periodically pushes soil up to make an air vent. At the same time, the eastern mole is tunneling just below the surface and you can walk on its created trail.
During the winter when the ground is partially frozen, both kinds of moles will push up piles of soil when they are active. They are feeding on earthworms and possibly grubs and soil insects. For more information on moles, see the MSU Extension article “ Moles in the lawn.”
Look for my upcoming article on what smart gardeners can do to discourage these dirty devils. Notice that it is “discourage” rather than “eliminate.” It’s tough to fight Mother Nature and her gang.
(Article written by Gretchen Voyle, Michigan State University Extension)