Why Do We Yawn?
User SciShow Kids on YouTube,
We yawn a lot when we're tired or warm, and sometimes we even yawn just because we see other people yawning! But why do we yawn…
We yawn a lot when we're tired or warm, and sometimes we even yawn just because we see other people yawning! But why do we yawn…
When you see someone yawn, you’re probably pretty likely to follow suit. But what makes it so contagious? Hosted by: Brit…