Humans are not the only organisms that have periods — some animals do too, but scientists still aren't sure why.

Research on whether animals can recognize themselves in the mirror began in 1970 1 and just a handful of species have since passed the test ever since.

Can chimpanzees wage war? In this excerpt from "The Beast Within: Human as Animals," scientific researcher Jessica Serra looks at the dark side of our cousins' behavior.

As of April 3, the man infected with B virus was still being treated in the ICU, health officials said.

Scientists have uncovered a consistent brain-wave pattern that erupts throughout the cortex in several primates, including us.

Scientists recently found that a so-called jumping gene may have jumped ship millions of years ago, and taken our tails with it.

Researchers discover a potential genetic connection between humans' tail loss and a type of birth defect.

Never smile with your teeth showing (or even yawn) at a monkey, as this could be considered threatening.

Scientists have created a healthy rhesus monkey clone by providing the cloned embryo with a healthy placenta, paving the way for more efficient cloning of primates and other mammals.

Gigantopithecus blacki went extinct at least 215,000 years ago after climate change caused its forest home to vanish.