Most hyenas are carnivores and eat any animal they can catch or scavenge, even insects. The spotted hyena is the only species of hyena that is considered an omnivore, or animal that eats both animals and plants.
All hyenas have very strong jaws and powerful stomach acid. This allows them to eat nearly every single part of a carcass, including hooves, teeth and bone. The only parts of the animal that hyenas can't digest are the hair, hooves and horns, though their digestive systems can extract nutrients from these things. Hyenas hunt their prey together as packs or scavenge for dead animals. Most of the time, hyenas eat at night.