Badgers may be seen above ground both day and night but do most of their hunting at night. Except for females with young, badgers are strictly solitary. Their presence in an area is indicated by large, eliptical burrows. Sometimes several of these burrows will be excavated in a roadside ditch or along a fencerow. These represent places where a badger dug up its fossorial prey. Badgers may use these burrows for a period of time before moving on. They forage over long distances in summer but stay closer to their burrows when the weather cools and remain in their burrows asleep during severe winter weather.
The badger eats mostly small and medium-sized burrowing mammals. Prey species include pocket gophers, prairie dogs, ground squirrels, mice, rats, and rabbits. Badgers also will eat, crayfish, birds and their eggs, insects, snakes, and carrion. Their diet differs seasonally and geographically with prey availability. Re-excavation of old burrows has been compared with running a trapline, as badgers feed on prey species that moved into old badger burrows after the badger moved on. A badger may dig "prospect holes" in the tunnel system of a pocket gopher until it locates the gopher; the badger then digs a badger-sized hole to capture the prey. It has been estimated that nearly three-fourths of such predatory bouts are successful.
Badgers have few natural enemies other than man. Young badgers may be preyed upon by coyotes or golden eagles, but adult badgers are fierce fighters that show little fear when approached by a larger predator. In fact, they have the disconcerting habit of standing their ground when confronted by humans. The primary causes of mortality of badgers are shooting, trapping, poisons, cars, starvation, and disease.
Female American Badgers enter estrous in late summer or early autumn. After fertilization occurs, implantation is delayed in the blastula stage until sometime between December and February. Birth occurs in late March or April, litters usually consisting of from 1 to 5 young. The young are hairless, and their eyes do not open for about 1 month. The litter is weaned at about 2 months. The father plays no role in provisioning the mother or young. Young badgers disperse in the autumn. Young females may breed at that time, but males do not breed until they are yearlings.
In captivity, a badger lived longer than 15 years. However, few badgers in the wild live longer than 2 years.