Photograph of three male zebra finches (Taeniopygia castanotis). In this study, more than 4,000 human participants from around the world were presented with pairs of animal sounds from 16 different ...

From the eerie croak of a tropical frog to the haunting call of the howler monkey, the animal kingdom is filled with some wild and wacky mating calls. But which do you find the most appealing?

AUSTIN (KXAN) — Is the mating call of a frog actually appealing to people? Researchers at the University of Texas are testing a surprising idea in a surprising way: humans and animals may have the ...

In the animal kingdom, penises can be spiked, split, corkscrewed—even detachable. They're one of the most diverse structures in biology. The human penis is so uniform, it's an anatomical outlier.