ELI5: Why do we yawn?

Imagine your body is like a car engine. Sometimes, it gets a little too hot or needs a little boost to run smoothly. Yawning is like that!

We don't really know exactly why we yawn, but here are some ideas from health experts:

• Cooling the Brain: Your brain is like the car's computer. When it gets too warm, it doesn't work as well. Yawning sucks in a big gulp of air, like opening the windows to let the heat out. This cools down your brain, helping it think better.

• Getting More Oxygen: Sometimes, we don't breathe deeply enough, and our bodies need a little extra oxygen. Yawning helps us take in a big, deep breath of fresh air, giving our body the oxygen boost it needs.

• Stretching Muscles: Yawning stretches the muscles in your face and neck. This can make you feel more awake and alert, kind of like stretching your arms and legs after sitting for a long time.

• Social Thing: Sometimes, we yawn because we see someone else yawning! It's like a little signal that says, "Hey, I'm tired," or "Maybe we should do something else." This is a social contagion.

• Keep your brain cool.
• Get more oxygen.
• Stretch your muscles.
• Maybe even tell others you're sleepy!