The color change, driven by hormones, seems aimed at preventing males from accidentally mating with each other.

Red fish are a favorite for both novice and expert fish enthusiasts alike, making them a popular choice for aquariums, large and small.

When monsoon rains begin to fall on the Indian subcontinent, Asian common toads congregate at temporary puddles for a ...

If you’re trying to find a date, you want to look your best, right? Snazzy outfit, slick hair, makeup on point – whatever it takes to get the best choice of partner in the Grand Annual Orgy. Sound ...

In arid parts of central Australia, temperature plays a big part in determining whether central bearded dragon embryos emerge from their eggs as male or female. While the sex of mammals and birds is ...

There’s plenty of rough sex in the animal kingdom, but dinosaur copulation may have been so violent that it literally broke ...

Scientists in Thailand have identified a new burrowing spider species, Damarchus inazuma, featuring a rare bilateral gynandromorph. This unique specimen displays distinct male and female ...

Michigan State University scientists have pinpointed the molecular "switch" that supercharges sperm for their final sprint to an egg—a breakthrough that could reshape infertility treatments and pave ...

A trans woman has been jailed for 21 months after tricking a young man by concealing male genitalia during sex acts carried out while they were on a date. Ciara Watkin, 21, a biological male with ...

Objective To quantify US female and male Olympic athletes’ longevity and the years of life lost or saved due to multiple causes of death as compared with the US general population. Methods Former US ...

A newly discovered species, Damarchus inazuma, displays a rare split-sex trait known as gynandromorphism and takes its name from a shape-shifting anime character. Jenny Lehmann is an assistant editor ...