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
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
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.
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.