Whether animals have language is the nature mystery people most want solved, according to a poll.
Asked to choose from 10 unanswered questions about the natural world, almost a third (31%) said whether animals use language was one of the issues they most wanted answered.
The second most burning question was about how the dinosaurs died out, with 29% of the 2,000 people polled putting that as one of their top queries.
And more than a fifth (22%) wanted to know why cats purr.
The poll for the launch of new TV show David Attenborough's Natural Curiosities on UKTV's Eden HD channel also revealed some of the most commonly believed myths about nature.
Almost half those polled (47%) believed female praying mantis eat the males after sex, although research has found that only happened once in 69 experiments, while 37% thought camels store water in their humps, rather than storing fat to provide energy.
The Natural Curiosities programme looks at some of the most extraordinary evolutionary anomalies of the natural world, including the giraffe's long neck, a zebra's stripes and the chameleon's long tongue.
David Attenborough's Natural Curiosities is on at 8pm on Tuesdays on Eden.