Burrow

A burrow is a hole or tunnel excavated into the ground by an animal to create a space suitable for habitation, temporary refuge, or as a byproduct of locomotion. Burrows provide a form of shelter against predation and exposure to the elements, so the burrowing way of life is quite popular among the animals. Burrows are also commonly preserved in the fossil record as a type of trace fossil.
Examples
Examples of burrowing animals include a number of mammals, amphibians, fish (dragonet and lungfish), reptiles, and birds (including small dinosaurs), as well as numerous invertebrates including insects, spiders, sea urchins, crustaceans, clams and worms.
A wide variety of animals construct or use burrows in many different types of substrate. Mammals are perhaps most well known for burrowing, especially Insectivora like the voracious mole, and rodents like the prolific gopher and groundhog. The rabbit, a member of the family Lagomorpha, is a well-known burrower...