Which animal lays eggs?
Eggs are used by every animal except mammals, and there is an exception there. Monotremes lay eggs such as platypus and echidna’s. So any animal from sponges, which yes they are animals, up to birds lay eggs. Mammals are the only main exception to “laying eggs” mammals instead keep eggs internalized and birth live young. In addition some sharks also birth live young. In short, some invertebrates, all insects, fish, reptiles, amphibians, birds, and monotremes lay eggs.
