There are about 110 species of swifts, and they are found on every continent except Antarctica.

Swifts are among the fastest-flying birds in the world and spend most of their lives in the air. They have long, narrow wings that form a boomerang or crescent shape when spread out, and many species have forked tails. Most swifts are dark-colored, with feathers that are shades of brown, gray, or black.

Swifts have very small feet and short legs. Unlike many birds that perch on branches, swifts usually cling to vertical surfaces such as cliffs, cave walls, chimneys, or buildings.

Their short bills open into wide mouths that help them scoop insects from the air as they fly. Swifts can eat, drink, sleep, and even mate without landing.

Many swifts build their nests in caves, on rocky cliffs, or on the walls of buildings. Some species use saliva to help hold their nests together.