The pits help them detect small animals, such as rats and birds, which are warmer than their surroundings. These heat sensors can tell temperature differences of one-hundredth of a degree Fahrenheit. Owls live in woods and forests. They rest in trees during the day. But as darkness falls they take to the air and begin to hunt.
Owls feed on mice, voles and small birds.
Sitting on a perch, a Barn Owl will listen for the slightest squeak or rustle from the ground below. To do this it moves its head from side to side, up and down, and almost right around. When it detects an animal the owl flies towards it, using its sharp vision to home in on its target. Owls' eyes are up to a hundred times more sensitive to light than ours, and they have the widest field of vision of any bird. Nightjars and nighthawks hunt insects at night.