Like many animals, owls have three eyelids. The upper eyelid closes downward when the owl blinks. The lower eyelid closes up when the owl sleeps. The third eyelid is called a nictitating membrane. This translucent eyelid moves horizontally across the eye and is especially useful when catching prey as the owl can still see while keeping its eyes safe from injury.

The smallest owl is the elf owl, which lives in the southwestern United States and Mexico. It will sometimes make its home in the giant saguaro cactus, nesting in holes made by other animals. However, the elf owl isn't picky and will also live in trees or on telephone poles.

Unlike most owls, burrowing owls are often active during the day, although they tend to avoid the midday heat. Like many other kinds of owls, though, burrowing owls do most of their hunting from dusk until dawn, when they can use their night vision and hearing to their advantage.

Owl eggs are typically white and almost spherical. They range in number from a few to a dozen, depending on species and season.

Most owls share an innate ability to fly almost silently and also more slowly in comparison to other birds of prey. However, they cannot use the preen oil or powder dust that other species use for waterproofing, which means they cannot hunt during wet weather.

Instead of spherical eyeballs, owls have "eye tubes" that extend deep into their skulls. As a result, their eyes are fixed in place, which means they have to turn their heads to see.

All owls are carnivorous birds of prey and live mainly on a diet of insects and small rodents such as mice, rats, and hares. Some owls are also specifically adapted to hunt fish or larger prey.

Owls are the primary means of communication between wizards in Harry Potter's world.

In Australia, the Wardaman tribe believes that Gordol the owl created the world.

The first Woodsy Owl public service spot was created by U.S. Forest Ranger Chuck Williams, who was the Forest Service's technical consultant for the Lassie TV show which featured a Forest Service Ranger and his family. In 1974, the U.S. Congress passed the Woodsy Owl Act (Public Law 93-318) to protect the character, making it a federal crime to reproduce his image.