Some species go extinct obviously and fast, but just as often, the process can be hard to detect until it’s too late.

Arguably the world's most abundant animal, calanoid copepods can leap like whoa Nelly. And check out their enigmatic embryos!

Gynandromorphy is an extremely rare condition in which an animal is half male and half female. It's most visible in birds and butterflies.

Meet the coconut crab, the largest terrestrial invertebrate on Earth.