A common swift that leaves its nest in late summer may not touch anything solid again until the next spring. When researchers in Sweden fitted small loggers to swifts, some of the birds flew for ten months without landing once. They eat insects on the wing, drink by skimming a lake in flight, and are thought to sleep up there too. Their legs are so short that the genus is called Apus, Greek for “footless”. Everything else a life needs, a swift does in the air. It comes down only to build a nest.