The space suits used by the astronauts on Gemini 7, known as grasshopper suits, were designed for comfort. But after two weeks inside them, that was the last thing on the crew’s minds.

There's a Limit to the Comfort Level of NASA Space Suits (3:32)

It's a partnership that's as unlikely as any: herds of bison on the move are kicking up chunks of earth. This, in turn, gives cliff swallows the valuable mud pellets they need to build their nests.

How Bison Are Helping Cliff Swallows Build Their Nests (3:38)

Greg Spriggs and Jim Moye are on a mission: to declassify all valuable film footage that exists of every U.S. nuclear test ever conducted.

Bringing Classified Nuclear Test Footage to the Public (1:47)

A flock of Andean condors have spotted a carcass in the Southern Cordillera region of Patagonia. It's a rare feeding opportunity in this barren land - and there will be a spirited competition for scraps.

These Condors Will Fight to Get a Seat at the Dinner Table (2:02)

The name sounds innocuous, maybe even charming. But it’s also known by another name—the ant lion—and it’s every bit as predatory and remorseless as that name sounds.

Doodlebug Is a Misleading Name for an Accomplished Assassin (3:04)

When birds need sleep, they do it on the fly--quite literally. They're able to enter a special kind of half-sleep state that lets them rest midair, which is especially important if you're a migratory bird, like the Alpine swift, clocking thousands of miles at a time. Glide into the astounding world of avian sleep.

The Secret World of Animal Sleep: Asleep on the Wing (3:01)

No bird is more skilled at in-flight feeding than a hummingbird, thanks to their ability to hover in the air. But if it's rainy, these fantastic flyers have to be extremely careful not to get hurt.

Why Hummingbirds Don't Like Flying in Rainy Conditions (2:17)

A military-grade thermal camera lifts the lid on the night time excursions of hippos on dry land. Those consist of grazing on a staggering amount of grass, while keeping a watchful eye out for roaming lions.

The Secret and Busy Night Life of Adult Hippos (3:27)

A shy orangutan makes great strides by confidently securing her share of breakfast. But she’s not above sharing her bounty of turnips with another orangutan, whom she’s befriended.