For these gregarious animals, 'alone time' is a fantasy.

Which species died out first because of humans?

Lacking human oversight, glitches in oil refineries and nuclear plants could lead to fires, nuclear explosions and fallout.

Pandemics, climate change, artificial intelligence: these are just some of the wide-ranging threats to humanity's survival. But they all have one factor in common...

For centuries, we plundered the ocean's depths, hauling up whales by the thousands. But what was the purpose of this dangerous and destructive industry?

This question reveals something much deeper about the ways we understand — and misunderstand — race.

How big can lightning get: Two miles long? Twenty? Fifty? Think again.

Our brains are ravenous, guzzling up to a quarter of the body's energy. So thinking really hard should be an easy way to burn more calories — right?

Head-bobbing might make pigeons look ridiculous, but there's a practical purpose behind this very strange display.

Several countries are launching claims to vast swathes of the Arctic seabed. But what does that mean for political and environmental stability in the region?

How many people could fit on the moon? Answering that may require asking other questions — about lunar survival.

The image of the hooded executioner is iconic, but it tells us only a small part of the story.

Beneath the Arctic lie billions of barrels of oil. But as the international energy race intensifies, we wonder, how did all that oil get there in the first place?

Could our most beloved fruit go extinct?

Is this expression really a smile?

We're making great strides in developing alternatives, but here's why it's still necessary to test on animals.

You may give them little thought beyond when to trim them or which nail color to apply. But the humble nail laid the groundwork for our evolution into the humans we are today.

It's not nearly as nonsensical as it may seem.

How many teeth can one mouth hold? You may be surprised.

These penguin dads are basically walking hot-water bottles.

The inventor of Comic Sans shares his thoughts about why so many people hate his creation.

Your home contains thousands of uninvited bacteria. Should you be worried?

Nut-obsessed squirrels might be smarter than you think.