Discovering reptile eggs during a nature walk or in your garden can be a fascinating experience. Although lizard eggs and snake eggs often appear similar, key differences in size, shape, texture, and ...

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 ...

New findings add a surprising twist to the already complex mechanism that determines whether reptile embryos develop to be males or females. An egg-laying lizard found in the hills of southeastern ...

Eggs helped animals conquer land—but most mammals stopped laying them. Why is that? Why do most animals lay eggs, while humans and most mammals give birth to live young? In this episode of Big Ideas ...

Fish and amphibian eggs are soft and unshelled and must float in the water in order to get enough oxygen and expel their ...