When can you start training a puppy? Why is the internet obsessed with Pesto the penguin? Time to test your baby animal ...

Instead, scientists often use the animal’s distinct calls—which sound like a crying newborn baby, the likely source of their name—to differentiate between closely related species.

This story appears in the May 2019 issue of National Geographic magazine ... Yet fish populations around the world, and the animals that eat them, depend on just how many larval fish make it ...