In the 1860s, the Australian Outback was the scene of major railroad expansion. At the heart of it was an unusual animal helping haul people and cargo alike.

The Unlikely Animal That Built Australia's Ghan Railway (1:41)

A rock rat is hiding from his predator, a honey badger, in the midst of a Namibian sweet thorn tree. But he doesn't count on his opponent's determination to get lunch, even at the price of a few cuts.

A Honey Badger Barrels Through a Sharp Thorn Tree for Lunch (2:37)

Grit the honey badger is on a mission to taste honey for the first time. To do so, he must break into a hive and withstand the fury of a bee horde determined to protect their home.

This Honey Badger Endures Bee Stings for His Favorite Treat (1:56)

King cobra mating techniques aren’t subtle. To indicate his interest, the male will engage in frequent headbutting with the female, while she dances provocatively around him.

Watch Two King Cobras Romance Each Other (2:17)

Over the years, the American buffalo, or bison, has been a symbol of the American frontier. As their numbers shrank, they began appearing on everything from the nickel to stamps to the $10 bill.

As the American Buffalo Declined, Its Symbolism Rose (1:17)

Chimps have a range of personalities and the facial expressions to reflect them. But perhaps the thing they most have in common with us is the ability to learn from each other.

Like Humans, Chimps Learn Behavior From One Another (3:27)

Blood vessels, intestines, the heart - all of the reed frog's organs are visible through its translucent skin. It's a great adaptation for camouflage...and just plain gross.

A Look Inside This See-Through Frog (1:01)

The caracal is a fierce and agile predator. And the way it pursues airborne prey is astounding.

Incredible: A Caracal Slaps Down a Bird in Flight (3:14)

When Jack scores a kill, all kinds of grassland creatures come out of the woodwork to steal it. Even worse, Jack's rival is secretly waiting to ambush him.

Two Leopards Battle, But Only One Can Survive (3:40)

With giant pectoral fins and colorful stripes, the lionfish is an imposing underwater predator. What's even more intimidating is how it hunts.

Stay Away From Packs of Hungry Lionfish (2:01)

Many plants rely on the wind to transport their seeds. However, in thick forests this system proved difficult. How did plants solve the problem?

The Sneaky Reason Why Plants Bear Fleshy Fruit (2:53)

Are hyenas the most misunderstood animals in the wild? They're intelligent, they have a sophisticated social order, and their famous laugh isn't even a laugh.

Why Do Hyenas Laugh? (3:38)

"Lion Whisperer" Kevin Richardson and a team of wildlife experts are handing out the final exams to their students of the South African plains. Watch these apex predators play a numbers game deciding how and who to attack.

How Lions Choose Their Prey (4:08)

Upon their arrival in Puerto Rico, killer bees caused one human death a year. But something strange began to happen...they became gentler.

Why Puerto Rico's Killer Bees Stopped Killing (4:35)

Every year, thousands of sharks pour in to the waters around the Socorros for a coordinated summer of feeding, and none of the other species are safe.

You've Never Seen This Many Sharks in One Place (3:20)

The electric eel generates electric shocks of up to 1,000 volts, 80 times the electric voltage of a car battery. Watch as a caiman learns this fact the hard way.

You Do Not Want to Get Tased by This Eel (2:04)

Crocodile's eyes are an engineering marvel: They can see all around, can track different targets, are retractable in battle, and can even see at night.

Astounding Facts About Crocodile Eyes (3:36)

The cuttlefish has the largest brain-to-body ratio of all invertebrates, which explains why its camouflage is so intricate and masterful.

This Color-Changing Mutant Has Three Hearts (3:10)

The tigerfish is one of the fiercest predators in the Congo River today. But one experienced angler isn't going to let that stop him from fulfilling a lifelong dream.

Would You Get This Close to a Goliah Tigerfish? (4:01)

Polar bears enjoy a good wrestle. It's an activity which reinforces social ties and may help get them in shape for the hunting season ahead.

Why Polar Bears Like to Wrestle in the Winter (1:37)