What is smell?

Smell is how we know what things are just by sniffing them, like knowing it’s your favorite snack without even looking at it.

Your nose works like a detective that can tell you who or what something is based on tiny invisible clues in the air. When you smell something, like cookies baking, little bits of the cookie go into the air, they're called molecules, and they float around until they get to your nose.

Inside your nose are special cells that catch those floating molecules. These cells send messages through your brain, telling it what you’re smelling. It's like when you drop a cookie on the floor, you can tell it's a cookie even if it’s all crumbly and broken.

Your brain is like a super smart librarian who has a whole shelf of smells already known to it. When those messages come in, your brain matches them up with what it knows, and poof, you know exactly what you’re smelling, just like knowing it's your favorite snack the moment you walk into the kitchen!