Reptiles were previously considered unable to play, but a Russian space experiment has overturned that view thanks to a loosely fastened collar

They can walk on walls with ease and shed their tails when they find themselves in a tight spot, but the one thing geckos were thought to lack was a capacity for playfulness. Now, a space experiment has overturned the view that geckos are entirely serious creatures, showing that they are open to a spot of fun after all.

When given the opportunity, the Russian experiment found, geckos are happy to spend time batting an object around a tank at zero gravity.

“Reptiles have quite a complex brain structure and rather well developed cognitive and perceptual abilities, but until recently they were considered unable to demonstrate play behaviour,” report the authors, from the Research Institute of Human Morphology in Moscow.

The findings mark more positive news for gecko-nauts, after it emerged last year that five geckos had perished on another unmanned mission, aimed at investigating weightlessness and sexual behaviour.

In the latest study, 15 female thick-toed geckos were sent into orbit on a 30-day unmanned mission aimed at studying gecko behaviour. The experiment was conducted using female geckos because male geckos tend to be extremely aggressive with each other, making it impossible to safely place more than one in the same container.

Shortly after take-off one of the geckos lost its collar, providing the animals with a floating toy. At first, the animals appeared to be avoiding the collar – possibly out of fear - but as time went on they started playing with it, watching it, batting it across the tank and pushing their snout into it so that it balanced on their nose.

The scientists ruled out the possibility that the geckos had mistaken the collar for food, because the reptiles did not respond in the same playful way when mealworms floated past (as seen in the video above). The geckos only caught and ate the worms, which were released every few days through a revolving feeder, when they were crawling on the walls of the tank and ignored any floating food.

Some geckos, it seems, are more playful that others. “Gecko No. 5 accounting for up to 39.4 % of play episodes,” the Journal of Ethology paper states.

By the end of the 30-day flight, the geckos had again become indifferent to the collar, which the authors put down to it having “become boring”.

Previously, animals including dogs, gerbils, newts, spiders, butterflies and mice have been launched into space. Much of the research is aimed at understanding the impact of spending time at zero gravity on physiology.