Holes in yards and landscapes often signal animal activity. Many animals instinctively dig for various reasons, leaving distinct clues about their identity. Understanding these excavations can help identify the responsible creature.
Common Mammalian Architects
Moles create characteristic molehills: volcano-shaped mounds of dirt without a visible entry hole, often appearing in lines or clusters. They also construct shallow surface runways, visible as raised ridges in the ground. Moles primarily consume insects and worms.
Gophers, small burrowing rodents, produce fan-shaped or crescent-shaped mounds of fresh soil, with the entrance hole typically plugged and located off to one side of the mound. Their extensive tunnel systems can span hundreds of square feet, reaching depths of up to six feet for nests and food storage. Gophers feed on plant roots and vegetables.
Groundhogs, also known as woodchucks, create larger entrance holes, usually 6 to 12 inches wide, often accompanied by a prominent mound of excavated dirt at the opening. These burrows frequently include a secondary escape hole. Groundhog tunnel systems can extend 15 to 25 feet horizontally and reach depths of up to six feet, providing separate areas for nesting, waste, and food storage. Their diet consists mainly of vegetation.
Other Mammalian Excavators
Skunks dig shallow, cone-shaped holes or divots, typically 3 to 4 inches in diameter, surrounded by a ring of loose soil. These excavations are made as skunks forage for grubs and insects.
Foxes dig dens that are larger and wider holes, frequently featuring multiple entrances. These dens are commonly found under sheds, decks, or within dense vegetation, serving as shelter and locations for raising their young.
Badgers are powerful diggers, creating large, deep, oval-shaped holes, measuring 20 to 30 centimeters wide. A substantial mound of dirt is typically present in front of these holes. Badgers primarily prey on rodents and insects.
Rabbits construct shallow scrapes or burrows, often in open areas or beneath shrubs. These excavations are used for shelter or to create nests for their young, known as kits.
Chipmunks create small, neat holes, approximately 1 to 2 inches in diameter, often hidden near rocks, tree roots, or building foundations. They are known for carrying excavated dirt away in their cheek pouches, resulting in no visible dirt mound around the entrance. Chipmunks dig primarily for food storage and shelter.
Beyond Mammals: Insect and Other Diggers
Cicada killer wasps produce perfectly round, pencil-sized holes, often with a small mound of excavated dirt around the rim. These are solitary wasps that dig these holes for nesting purposes.
Ground-nesting bees create small, often dime-sized holes, sometimes clustered together, occasionally with a small dirt mound around the opening. These bees are typically docile and play a beneficial role as pollinators.
Ants construct very small holes, varying in size depending on the species, which are typically surrounded by fine, granular dirt mounds. These mounds serve as entrance points to complex underground nests and tunnel systems that can span several meters deep.
Some reptiles and amphibians also engage in digging. Turtles, for example, dig shallow, bowl-shaped depressions or flask-shaped nests in the ground using their hind flippers to lay eggs. Snakes may utilize existing burrows for shelter rather than digging their own.
Certain bird species are also burrowers. Burrowing owls often use abandoned burrows dug by other mammals like prairie dogs or badgers, though they can excavate their own, creating openings 4-6 inches wide with a mound of dirt at the entrance. Kingfishers dig burrows for nesting, typically in riverbanks, with tunnels that can extend up to a meter deep.
Why Animals Dig and What Their Holes Mean
Animals dig holes for several fundamental reasons, each serving a specific survival purpose. A primary motivation is seeking shelter from predators, harsh weather conditions, or to regulate body temperature. Many animals also dig to find food, such as grubs, worms, or plant roots, which are often located underground. Digging provides a means for animals to store food safely for later consumption. Holes also serve as secure locations for raising young, offering a protected environment for nests or dens.
Animal digging contributes to soil aeration and improved water infiltration. Observing the characteristics of holes over time can help confirm ongoing animal activity.