Owls are birds, and most owls are awake and hunt at night. Owls have big eyes, but owls cannot see in total darkness, and 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. An owl's eyes are fixed in its skull by a bony ring, so the owl has good two-eyed vision but must turn its head to see to either side. An owl can turn its head far around to look behind it, and it bobs and sways its head to judge distance.

Now let's look at how owls hear. An owl's ears are holes in its head, hidden under feathers, and the ring of feathers around an owl's face, called the facial disc, helps funnel sound to its ears. An owl's facial ruff and disc form parabolic troughs that lead to the ears and can increase sound pressure tenfold. Owls hear low-frequency sounds better than most birds do, and they are sensitive across a wide range of frequencies. 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.

Next, let's look at how owls fly. Many owls fly almost without a sound, and owl wings quiet the air in three ways: a stiff comb on the front edge of the outer feathers, soft fringes on the back edge, and a soft, downy covering on the feathers. Owls have large wings for their body size, which lets them fly slowly. A large owl such as a barn owl can fly as slowly as two miles per hour, gliding with little flapping. Silent flight matters less to owls that hunt over water or by day, and many of them lack the quieting feather features.

Most owls hunt by sitting and waiting on a perch, then dropping or gliding down, and only light-winged owls such as the long-eared and short-eared owl hunt much in the air. Owls eat many kinds of prey, from small mammals to birds, lizards and insects, and a few owls eat fish. Barn owls eat many rats, mice and voles, and a snowy owl's favorite food is lemmings. The size of an owl's feet is usually a sign of how big a prey animal it can take, and owls grab their food with sharp claws called talons. In one study, voles froze longer when they were near white-bellied barn owls than near red-bellied ones.

Owls have no teeth, so they often swallow their food whole. They cough up pellets of fur and bones that they cannot digest, and 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, and owls help people by eating rodents such as mice and rats.

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. In Washington State, scientists have built artificial burrows for western burrowing owls from corrugated drainpipes that lead to a nest chamber in a 55-gallon barrel. Owls lay more eggs when there is plenty of food and fewer when food is scarce. Owls are hard to study in the dark, and much of their socializing is done with their voices.

Let's finish with how many kinds of owls there are and how some of them are doing in the wild. 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. Between 1966 and 2013, burrowing owls in North America declined by 33 percent, and as of November 2026 their numbers have been going down for many years, mostly because they are losing places to live. In 1993 the U.S. Fish and Wildlife Service listed the Mexican spotted owl as threatened under the Endangered Species Act, and in 2004 it designated critical habitat for the owl.

Words to know

• corneas: clear eye covers
• pellets: fur-and-bone balls
• parabolic: bowl-shaped curve
• frequencies: sound pitches
• burrows: holes underground