Why did our ancestors ditch the shell and start growing babies inside their bodies instead? In this episode of Big Ideas, ...

Platypuses are weird looking. They look like someone stitched together a duck and a beaver—flat bill, webbed feet, and a ...

Q. When we studied high school biology, our teacher said more than 99 percent of animals lay eggs and only a few give live birth. That percentage seems too high. Humans, dogs, cats and cows are ...

Even within the world of egg-laying animals, there is an incredible variety of reproductive strategies. Some species mate before the female lays her eggs, ensuring they are fertilized internally, ...

This video explores the life cycle of various animals including butterflies and frogs, showing how animals change as they ...