They are about 29–55 cm (11–22 in) long. They are nocturnal omnivores that do not need to drink water, as they obtain their moisture from food, which includes insects and their larvae, seeds, spiders, bulbs, fruit, fungi, and very small animals. Most food is found by digging or scratching in the soil, and using their very long tongues.

Bilbies build extensive tunnel systems with their strong forelimbs and well-developed claws. The female bilby's pouch faces backwards, which prevents the pouch from getting filled with dirt while she is digging.

Bilbies have a short gestation of about 12–14 days, one of the shortest among mammals.