Got your finger up your nose? (We hope not!) If you do, you can probably feel a
booger. Boogers are made of
dried mucus, dust, pollen,
and dirt. They can be squishy or hard, but they do an important job — they help
keep that bad stuff from getting into your lungs. Since boogers are full of germs,
it's a good idea not to pick them (blow them out into a tissue instead).