Why are whale sharks called whale sharks? Why are guinea pigs called pigs if they're not pigs? Why are eagles called bald eagles if they're not bald? You also ask us lots of questions about why and how animals got their names. So today we're going to introduce you to the concept of taxonomy, or how animals are categorized, and we'll also talk about the difference between scientific and common names. We'll learn about the reasoning behind the names of daddy long legs, killer whales, fox snakes, German shepherds and more! Our guests are Steve and Matt Murrie, authors of The Screaming Hairy Armadillo, and 76 Other Animals With Weird Wild Names.

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There are some animals whose names don't really seem accurate-like daddy long legs...which certainly aren't all daddies! Or bald eagles that very clearly have plenty of feathers on their heads. Or guinea pigs, which aren't actually pigs!

And then there are animals with awesomely silly names. Have you ever heard of the umbrella bird? How about the sparklemuffin peacock spider!  Or the monkeyface prickleback, the sarcastic fringehead, and the white-bellied go-away bird!

How do animals get their names? Well, there are two types of animal names: Scientific names and common names.

Scientific names are used as a way to categorize all living things, so even if you don't know a lot about an animal, you can learn a lot about them by knowing their scientific name. There are eight different levels that living things get grouped into: domain, kingdom, phylum, class, order, family, genus and species.

The broadest category is called the domain. There are three domains: archaea, bacteria, and eucarya. Bacteria and archaea are both categories of micro-organisms. All animals and plants belong in the eucarya domain.

Below domain is kingdom. There's a kingdom for animals called Animalia and a kingdom for plants called plantae. (And a few others as well.) As you go through the classification system it gets more and more specific. So, take humans: we belong to the eucarya domain, the animalia kingdom, the chordata phylum (because we have a backbone), the mammalia class (because we're mammals), the primate order, homonidae family, homo is our genus and homo sapien is our species name.

All species have two official scientific names, kind of like how you have a first name and a family name. So the species name for humans is homo sapien. The species name for a common black rat is rattus rattus. An Asian elephant is elephas maximus.

Those names sound fancy, and originally the scientific names of animals were in Latin or Greek, but they don't have to be Latin or Greek anymore, they just have to sound like they are!

But we don't typically call all animals by their scientific names. We often refer to them by their common names, which are kind of like nicknames! Common names can be different in different languages. Like, the scientific name for a wolf is canus lupus. That would stay the same no matter what language you're using. But in English we tend to call it a wolf; in Spanish you'd call it un lobo, and in Welsh it would be blaidd (pronounced "blythe").

Even within the same language, an animal can have lots of common names. Here in Vermont, where I live, we have an animal called a groundhog. But most people around here call it a woodchuck. And others call it a land beaver, or a whistle pig! Common names were often in use long before animals go their specific scientific names.