For the vast majority of species, the easiest way to tell an animal’s biological sex is to check out its junk. Does its sex organ elongate and stick out sometimes? A male, in most cases. Is it more ...

Breakthroughs, discoveries, and DIY tips sent six days a week. Terms of Service and Privacy Policy. Researchers in Denmark have discovered six new species of beetle ...

Females of a cricket-like insect found in New Zealand consume male ejaculate after sex to give them enough energy for the following six months of parenting, when they don’t eat. The size of the ...

Scientists have discovered four species of Brazilian insects in which the females possess a penis and the males possess a vagina. This announcement, made today in the journal Current Biology, ...

Seven species of a frog-like insect that were discovered in a rainforest have been confirmed as new to science following an examination of their genitalia. The previously unknown species of leafhopper ...

What purpose does the penis serve? Why is it that members of one species have no penis at all, while those of another have two? Why do they vary so much in shape and size? And where do vaginas, or the ...

If you looked at the penis of a Drosophila fly under a microscope (for reasons best known only to yourself), you’d see an array of wince-inducing hooks and spines. These spines are present in all ...

She says when male and female insects look different, that is called sexual dimorphism – and this can happen in a variety of ...

The most dramatic genital-shape reversal known — females with long, insertable organs and males with corresponding pouches — has turned up in bark lice living in Brazilian caves. A female in each of ...