Some people might claim that homosexual sex is "unnatural," but they are mistaken. Homosexual sex is actually rather rampant in nature, especially among insects. In fact, up to 85 percent of male insects and spiders regularly engage in homosexual acts.

The hows and whys of all this indiscriminate insect sex have long puzzled researchers, however, since such acts do not directly produce offspring. But a new study by Doctor Inon Scharf of Tel Aviv University and Doctor Oliver Martin of ETH Zurich University has finally gotten to the bottom of the mystery, reports the Independent.

It turns out that it's all a case of mistaken identity. Bugs everywhere are having gay sex entirely by 'accident.'

The study looked at 110 species of male insects and spiders and found almost no evolutionary advantage to insect homosexuality. But this little fact didn't seem to make much of a difference in the grand scheme of things. In fact, most insects and spiders have not even bothered to evolve a way to properly discriminate between males and females. Although this leads to a number of matings that cannot produce offspring, straight sex still happens often enough for it not to matter.

"Insects and spiders mate quick and dirty," explained Dr. Scharf. "The cost of taking the time to identify the gender of mates or the cost of hesitation appears to be greater than the cost of making some mistakes."

The results are a bit surprising because sex of any kind can carry a significant cost of energy and time. Sex can even be dangerous for some species, such as with those that risk being cannibalized. But this risk was still not enough of an evolutionary pressure to make homosexual encounters less common.

Researchers also suggested that some gay insect sex could be the result of males accidentally becoming 'dressed' as females. This can happen when males are carrying female pheromones which have rubbed off from a previous heterosexual encounter.

"Even though misidentifying mates isn't a desirable trait, it's part of a package of traits that leaves the insect better adapted overall," explained Scharf.

Homosexuality isn't just an insect or spider thing; it's been observed in other invertebrates too, such as among crabs, octopi and even worms. Most classes of vertebrates engage in gay sex too, including birds, mammals, reptiles and amphibians.

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