Spider-Man has much in common with the male spiders whose powers he emulates, a study has found.
Like the comic book hero, male spiders of many forest species are adept at flinging out lines of silk that help them cross wide regions of empty space.
The same ability allows Spider-Man to leap between skyscrapers in New York with effortless ease.
Scientists believe the acrobatics of male spiders can explain why they are so much smaller than the females.
Being small assists their superhero-like antics and those that are better at the technique -- known as "bridging" -- are more likely to find a female to mate with.
Natural selection therefore favours male spiders being small. In contrast, being big confers an advantage to female spiders by helping them produce offspring.
Guadalupe Corcobado, from the Spanish National Research Council studied 204 spiders' bridging behaviour in a wind tunnel to make the findings.
He said: "Small males, by being more efficient bridgers, will enjoy more mating opportunities and thus will be better at competition to reach receptive females."
Typically the "bridging" method of travel involved using the wind to carry a strand of silk to a chosen destination. The spider then clambered upside down along the resulting "bridge".