Owls are birds, and most owls are awake and hunt at night. As of November 2026, scientists recognize more than 200 kinds of owls, and they are sorted into two families: barn owls, and all the other owls, called typical owls. The biggest owls weigh up to about 9 pounds (4 kilograms), while the elf owl is one of the smallest owls in the world. Owls have big eyes, but owls cannot see in total darkness. So how do they hunt in the dark, and how does the body of an owl help it find food after sunset?

Owl eyes are shaped like tubes, not balls. Owls have small skulls, so their big eyes, which need large corneas to collect light, could not grow outward and took a rod shape instead. Behind an owl's retina is a mirror-like layer called the tapetum. It reflects light that the rods and cones did not absorb back through the eye, giving the receptor cells a second chance to catch it. Owls cannot move their eyes around, so they turn their whole heads instead, and they bob and sway their heads to judge distance.

An owl can turn its head far around to look behind it. An owl's ears are holes in its head, hidden under feathers, and the ring of feathers around its face, called the facial disc, helps funnel sound to its ears. An owl can hear a mouse step on a twig from about 75 feet (23 meters) away, and a great gray owl can find a rodent under the snow by sound. Many owls fly almost without a sound, and the outer wing feathers have a comb-like edge that helps quiet their flight.

The edges of an owl's feathers are soft, and owls have large wings for their body size, which lets them fly slowly. A snowy owl is a patient hunter that waits on a perch and then flies after its prey. Owls grab their food with sharp claws called talons. Owls catch small animals such as mice to eat, and they eat many kinds of prey, from small mammals to birds, lizards and insects. A few owls eat fish. Barn owls eat many rats, mice and voles, and a snowy owl's favorite food is lemmings. Owls help people by eating rodents such as mice and rats.

Owls have no teeth, so they often swallow their food whole. They cough up pellets of fur and bones that they cannot digest. Because the digestive juices of an owl's stomach are not as acidic, owl pellets contain the bones of the owl's previous meal, along with fur, feathers or insect parts. Taking apart an owl pellet shows what the owl ate, and scientists have found species they did not know lived in an area by digging through owl pellets. Many owls also hide extra food and come back to eat it later.

Most owls do not build their own nests, but use old nests of other birds or holes in trees. Burrowing owls often use burrows dug by other animals, such as prairie dogs, ground squirrels and badgers, rather than digging their own. Most owls stay in the same area all year, and very few kinds of owls migrate. Owls lay more eggs when there is plenty of food and fewer when food is scarce, and some owls skip breeding in years when food is scarce. Between 1966 and 2013, burrowing owls in North America declined by 33 percent. As of November 2026, their numbers have been going down for many years, mostly because they are losing places to live.

Words to know

• tapetum: mirror-like layer
• pellets: fur-and-bone balls
• facial: of the face
• migrate: move far away
• burrows: holes underground