Being a mother is a tremendous accomplishment and one of the most challenging jobs in the world. This applies even in the animal kingdom, where it can be a literal dog-eat-dog world for many species.

This article is republished from The Conversation. Ask any parent—welcoming a new baby to the family is exciting, but it comes with a lot of work. And when the new addition is a pair of ...

Some animals are pregnant for a long time – nine months or more. To have spring babies, they need to fertilize their eggs in ...