When tunnels begin crisscrossing your neatly tended grass like mismatched plaids, the odds are favorable that your yard is playing host to any of several burrowing animals or two tunneling insects. The tunnels provide the best clues to their occupants' identities.
Tunnels with Mounds
Moles often tunnel along garden beds and walkways, where the soil has been cultivated enough for them to dig easily.
Pocket gophers often burrow beneath well-irrigated lawns. Their tunnels lie 6 inches to 1 foot underground, with no visible ridges. Crescent-shaped mounds sealed with soil plugs guard their entrances.
Cicada Killer Wasps
At nearly 2 inches long, cicada killer wasps are hard to miss. They're named for their habit of injecting paralyzing venom into cicadas and caching them underground to feed their young. The female wasps usually tunnel in bare, sandy soil, but closely cropped grass will do.
The wasps' tunnels are 6 to 10 inches deep, with the excavated soil scattered in semicircular mounds around their sealed, 1/2- to 1-inch-diameter entrances.
Tunnels with No Mounds
Although voles -- also called meadow mice -- spend most of their lives in underground burrows, they also make networks of above-ground runways hidden beneath deep grass or other vegetation. Each runway leads to a burrow entrance hole roughly 1 1/2 to 2 inches wide.
Thirteen-lined ground squirrels usually dig in open areas. So neatly mowed lawns are right up their alley. Their tunnels typically measure 15 to 20 feet long and often have several 2-inch diameter entrance holes.
- Ground squirrels scatter the soil they excavate around their tunnels' entrance holes instead of piling it into mounds.
- Chipmunks often get blamed for ground-squirrel tunneling. In reality, chipmunks avoid the open areas that ground squirrels prefer. Chipmunks usually tunnel in the shelter of shrubs, trees, walls, woodpiles or rock piles.
Using their stout front legs with feet made for digging are how 1-inch-long mole crickets tunnel their way underground to feed on plant roots. Mole cricket-infested grass wilts and pulls from the soil without resistance. In home lawns, the insects' tunnels appear as finger-wide ridges.
To verify a mole-cricket infestation, start by waiting for warm weather and watering the grass well. Then mix 2 tablespoons of liquid lemon dish soap with 1 gallon of water, soak the tunneled area with the mixture and wait five minutes to see whether or not mole crickets emerge from the ground.
- Washington Department of Fish and Wildlife: Living with Wildlife -- Moles
- University of California Integrated Pest Management: Pocket Gophers
- University of Georgia Center for Urban Agriculture: Cicada Killer Wasps
- Clemson Cooperative Extension: Holes in the Lawn
- University of Nebraska-Lincoln Extension: The Thirteen-Lined Ground Squirrel -- Controlling Damage
- Forest Preserve District of DuPage County, Illinois: Chipmunks and Ground Squirrels
- University of Georgia Extension, Houston County: Mole Crickets
Passionate for travel and the well-written word, Judy Wolfe is a professional writer with a Bachelor of Arts in English literature from Cal Poly Pomona and a certificate in advanced floral design. Her thousands of published articles cover topics from travel and gardening to pet care and technology.