It's not just tennis players – grunters are everywhere. And they're not to be trusted | Andre Spicer

From archaeologists to office workers, people feel the need to accompany hard work with a grunt. But why do they do it?

When the umpire at Wimbledon calls out "quiet, please", a religious hush falls over the court. The only things that break the silence are the gentle pop of a bouncing tennis ball, the faint murmur of the crowd, and the passionate grunting of the players.

Related: What can science tell us about grunting in tennis?