When geckos play ball and spiders spar: The strange evolution of fun

The ability to play is being spotted in some unexpected creatures, from swans to Komodo dragons. Are they really fooling around? And if so, why do they do it?


15 December 2021

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Graham Carter

AS I write, my kitten is having a funny 5 minutes – or rather a funny 2 hours and counting. A toy mouse has been thoroughly tortured and my laptop keyboard co-opted for a tap-dancing session.

It seems obvious to me that Peggy is playing, and that she is enjoying herself. We are used to the idea of certain warm-blooded creatures, especially our pets, larking around. But what about a crocodile toying with a ball or Komodo dragons playing tug of war with their keepers seemingly for the hell of it?

It could be that these animals really are playing – or that we are projecting our own playful nature onto their behaviour. “There’s lots of anecdotal little stories out there,” says Gordon Burghardt at the University of Tennessee, Knoxville. In the past, “without photographic or film evidence, they could be easily dismissed by scientists”, he says. Today, though, evidence of play in unexpected creatures is building. Biologists have reported examples from the furthest reaches of the animal kingdom: not just primates and house pets, but reptiles, fish, octopuses and even spiders and wasps. Play isn’t universal, says Burghardt, but it is more common than was once thought. So why is it beneficial to spend time mucking about?

To answer this, we need to understand how and why the capacity to play evolved. A key problem is how to define play – especially as we can’t ask animals if they are having fun. Many thinkers have tackled this question, and Burghardt has attempted a synthesis of the various definitions. He devised five criteria for whether a behaviour counts as play. The action …