A. The holes could be rat burrows, especially given their location, but keep in mind that other animals (such as meadow voles, moles, and deer mice) can also dig burrows in your yard. In buildings, brown rats (also called Norway rats) can nest almost anywhere – in wall or ceiling voids, in upholstered furniture, in attics or crawlspaces. But in their natural habitat outdoors, brown rats are burrowers.

Rats especially like to burrow under rocks, concrete slabs, or other heavy objects. They are notorious for digging burrows under the concrete slabs that dumpsters sit on. Here they have a cozy home with ready access to food from the dumpster. They also burrow in thick ground vegetation like English ivy or under low, thick shrubbery.

The rat burrow itself rarely goes farther down in the ground than 18 inches but can be much deeper when rats are trying to dig under foundations. Burrows are usually less than 3 feet long with a central nest area filled with leaves, grass, or soft debris.

The size of the burrow opening is often the key to whether you are dealing with rats or some other burrowing animal. The main opening to a brown rat’s burrow is 2 to 4 inches in diameter and is smooth from use. The opening will often have freshly excavated dirt strewn in a fan shape around the outside of the opening. To tell whether a rat burrow is still active, pest management pros often fill the burrow with debris or partially collapse it, then check back to see whether the rats have reopened the entrance. A rat burrow will have extra bolt, or escape, holes as well. These secondary holes may be hidden under objects or even lightly plugged with dirt.

Our experts at Colonial can determine just who is doing the digging. The pests in question can be trapped or burrows can be carefully treated with rodenticides. Give us a call. Look for more information about brown rats in our website’s Pest Library.