ELI5: Explain Like I'm 5

Olfaction

Have you ever smelled something yummy cooking in the kitchen? Or maybe you smelled something stinky like rotten trash? Well, we use our sense of smell to detect different scents and that is called olfaction!

Our nose has special cells called olfactory receptors that can detect different molecules in the air. When those molecules enter our nose, they bind with the olfactory receptors which then send signals to our brain telling us what we are smelling. That's how we know if we are smelling something good or bad!

Fun fact: Humans can detect around 10,000 different scents!