Finding a mate is hard in the animal kingdom! As these strangest animal mating rituals show, it sometimes gets even more ...

Some animals reproduce only once before dying. This life strategy, called semelparity, sees organisms channel all energy into reproduction. Mechanisms include stress hormone overload, sexual ...

All animals need sleep. When humans or animals don't get enough, it can lead to trouble paying attention, irritability, and other ill effects. And yet, researchers reporting in the journal Current ...

Koalas have a well-earned reputation for being dopey. Sleeping 19 hours out of every 24, and feeding for 3 of the remaining 5 hours, there doesn't seem to be much time for anything else in their ...

For some animals, reproduction comes at the ultimate cost—their own lives. While this may seem extreme, it's a natural strategy to maximize reproductive success. These species invest everything into ...