How do we smell? - Rose Eveleth?

We smell things because tiny parts inside our nose help us know what’s around us, like how a detective can tell who is nearby just by sniffing the air.

When you smell something, like your favorite cookie, it starts with tiny particles floating in the air. These are called molecules, and they come from the cookie as it bakes or cools down. They travel through the air until they reach your nose, kind of like how a message is passed from one friend to another in a game of telephone.

Inside your nose, there are lots of little helpers called smell cells (or olfactory receptors). When those tiny molecules touch them, it sends a message up to your brain. Your brain then says, “Oh! That’s cookies!”, just like how you know when someone is knocking on the door because you hear the knock.

Sometimes, your nose can tell the difference between similar smells, like vanilla and chocolate, kind of like how you can tell apart your brother and sister by how they sound or move. Your brain does all this quickly, so you don’t even have to think about it!