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

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 ...

Snakes, like most reptiles in the world, are oviparous. This means that rather than producing live young ones, the way mammals do, snakes produce an immature single cell — an egg. Most snakes follow ...

Monotremes are a class of mammals that are known as egg laying mammals; they are a special group of mammals that lactate to ...