Body & Health
How many bones do humans have?
206 bones
Why do we laugh?
To show happiness, relax, or connect with others.
How fast does hair grow?
About 1 cm (0.5 inches) per month.
Why do humans fight?
Often because of fear, anger, or wanting resources (food, money, power).
Why do we forget things?
Your brain cleans out unused memories to save space (like a computer!).
Why do we blink?
To keep our eyes wet and clean.
Why do people cry?
To release stress or show strong emotions (sadness, joy, pain).
Why do we have fingerprints?
To grip things better and help with touch sensitivity.
Why do people help strangers?
Kindness is natural—it helps groups survive and feel good.
Can humans smell as well as dogs?
No! Dogs have 300 million smell receptors—humans only have 6 million.
Why do people yawn?
No one knows for sure! Maybe to cool the brain or get more oxygen.
Why do we dream?
Scientists think it helps with memory and emotions.
How many muscles do we use to smile?
About 10–12 (but only 2 to frown!).
Can humans live forever?
No, but science is trying to help us live longer (like with medicine and robots).
Why do some sounds make us cringe (like nails on a chalkboard)?
Our brains think they’re danger signals—like a baby’s cry or a scream.