|Common swift, Apus apus|
Note wing shape different from swallows
The scientific name for the swift (apus) comes from the Ancient Greek word απους, apous which means "without feet". This is because swifts have very small, weak feet. Swifts use their feet to hold on to vertical places (for example, the wall of a house, or a cliff). Swifts do not want to land on the ground. It is often thought that if they land on ground, they cannot fly up again, but that is not true. They can take off but with difficulty.
Swifts are small birds. They can fly very well and very fast. Some swifts can fly at 5–14m per second. If a swift needs to fly very fast, it can fly at 60m per second for a short amount of time. When catching insects, they fly in a series of swoops, changing direction rapidly as they pursue the prey.
Swifts can be seen all over the world. They like to live in warmer places and they migrate every year. For example, Swifts fly to Europe in the spring and summer. When it gets cold at the start of autumn, the Swifts fly to Africa where it is warmer.
There are some swifts which only use saliva to make their nests. These swifts are in the genus Aerodramus. In Asia, people take the nests and use them to make bird's nest soup. This soup is very popular in China.