Males and females of some species fight viciously. Though they are usually not trying to kill each other, the fighting can result in death.

From insects that look like leaves and snakes that play dead to flying fish and poisonous toads, animals defend themselves in fascinating ways.

With predators always looking for a meal, their prey must constantly avoid being eaten. Defensive adaptations add to their chances of survival.

Crocodiles are descended from animals that roamed Earth 250 million years ago, while snakes rely on the sun to control their temperature.

There are many fine examples of evolutionary history in the natural world. Whales evolved from land-dwelling creatures to today's marine mammals.

Attack and escape scenarios involving avian predators and their prey, including horizontal speeding and diving to avoid capture.

There are many reasons why insects survive, from strong, flexible shells to wings that give them the option of flying away from danger.

Desert animals have evolved to handle heat and lack of water. This includes scorpions, which have existed since life first crawled from the sea.

The African Savannah sees thousands of battles each day. How do elephants survive on a diet that even the strictest vegetarian would avoid?

The leopard is perhaps the best-equipped big cat, with a population spread far and wide, but lions have almost no predators.

Almost all animals living in the sea have bodies designed for hunting or protection, and predators have adapted extreme measures to survive.

Protecting themselves underwater is a matter of invention and reinvention, so aquatic animals deploy an array of strategies just to stay alive.

Protecting themselves underwater is a matter of invention and reinvention, so aquatic animals deploy an array of strategies just to stay alive.

Nocturnal animals use the dark to escape predators, avoid the heat of the day, and take turns sharing food and resources.