Burrowing involves animals excavating holes or tunnels in the ground for habitation or temporary refuge. This behavior is widespread across the animal kingdom, seen in various species from tiny insects to larger mammals. The excavated structures provide shelter and are found in nearly every biome on Earth. Many animals depend on these underground dwellings for their survival and daily lives.
Reasons Animals Dig Underground
Animals dig underground for survival. Primarily, burrows offer shelter from predators, providing a safe, fortified environment. These enclosed spaces also offer a quick escape route when danger approaches.
Burrows also protect from extreme weather. Underground temperatures remain stable, helping animals regulate body temperature and conserve energy. This stability is especially beneficial in harsh climates.
Burrows serve as nurseries for raising young, protecting offspring from elements and predators. Some species also store food, keeping supplies safe and accessible during scarcity.
Common Mammalian Burrowers
Many mammals are known burrowers, creating intricate underground homes. Prairie dogs, for instance, construct extensive “towns” with complex tunnel systems. Their burrows often include chambers for sleeping, raising young, and waste disposal, with mounds at entrances serving as lookout points and aiding ventilation.
Badgers dig elaborate setts, networks of tunnels and chambers. These setts are spacious, accommodating multiple badgers and often featuring several entrances. Groundhogs are also proficient burrowers, creating dens with multiple entrances that offer escape routes from predators. Their burrows can extend up to 24 feet and include separate chambers for hibernation below the frost line.
Moles are specialized burrowers, creating extensive tunnel networks primarily for foraging. Their systems vary in depth, with shallower tunnels for surface food and deeper ones for drier conditions. Gophers build complex burrow systems, featuring main burrows, lateral tunnels, and deeper chambers for nesting and food storage. Rabbits are known for their warrens, large, interconnected systems used by social groups.
Other Fascinating Underground Dwellers
Beyond mammals, many other animals also burrow for survival. Among reptiles, snakes like hognose and sand boas are adept burrowers, using specialized snouts to dig. Some lizards, including skinks, also burrow for shelter; mole lizards are highly adapted, with reduced limbs and streamlined bodies.
Amphibians like spadefoot toads dig backward into soil, creating temporary burrows to escape harsh conditions. Caecilians, limbless amphibians, are highly adapted for burrowing, resembling worms or snakes and spending most lives underground. Many insects burrow, including dung beetles burying dung for eggs and mole crickets with powerful forelegs. Cicada nymphs spend long lives underground, feeding on roots before emerging. Spiders like trapdoor spiders construct burrows with hinged lids to ambush prey; scorpions and crabs also dig for shelter.
Ingenious Ways Animals Construct Burrows
Animals employ various adaptations and techniques to construct their burrows. Many mammalian burrowers, such as badgers and moles, possess powerful forelimbs with strong claws for excavating soil. Moles, for instance, have large, spade-like forepaws that move in a swimming-like motion to displace earth.
Gophers utilize claws and specialized teeth for digging. Their prominent incisors can gnaw through soil or roots. Some animals, like armadillos, use powerful snouts with claws to break up soil. Mole crickets feature enlarged, shovel-like front legs with blade-like projections to tunnel effectively. After loosening soil, many burrowers kick excavated material out or push dirt to the surface, forming mounds.