You know the feeling. It’s impossible to resist. You just need to yawn. A yawn consists of an extended gaping of the mouth followed by a more rapid closure. In mammals and birds, a long intake of ...

Simply looking at the word can stimulate a yawn. I’m actually yawning while typing this piece. Interestingly, all vertebrates — a living being with a spinal column — yawn. Vertebrates include mammals, ...

We do it when we're tired, when we're bored or when we're hungry; parachutists have been seen to do it before a jump, and research has even suggested a link between yawning and sexual arousal. But the ...