You can interpret the image as either one of these animals or the other, but not both at the same time.

It's the former Yugoslavia's fault.

If asked, spotted owls would likely vote against marijuana legalization.

The thresher sharks likely didn't die of hypothermia.

The long-extinct sea predator flourished during the middle Cambrian period about 508 million years ago.

In a submerged cave network in the Yucatan, methane is an unlikely driving force for life.

Scientists have converted a bunch of microbes into what they've dubbed the "world's smallest tape recorder."

The bustling octopus community of "Octlantis" belies conventionally held notions of the cephalopods, once thought to be solitary and asocial.

Anyone who has experienced the euphoric "runner's high" that follows a satisfying workout will likely attest to a connection between physical activity and mental health.

Being overweight or obese increases a person's risk for at least 13 types of cancer, according to a new report.

From inefficient grids, shortfalls in policy, and even an eclipse, solar-energy collection faces no shortage of hurdles. Scientists have discovered another stumbling block: air pollution. 

Want to get off the grid? Here's what it'll cost you.

Rising temperatures are affecting the animal kingdom in many subtle ways.

Sharpen your environmental vocabulary.

A heated battle of blame is in full swing. Here's what's known.