Why bugs bite and sting

Have mosquitoes ever eaten you alive? Or has a bee or wasp ruined your picnic when it didn't leave you alone? Sometimes insects can drive you buggy. Most aren't very dangerous, but it's no fun when they bite or sting.

Why do they do it? Some bugs, like mosquitoes and ticks, need to suck blood to stay alive. Others, like bees, wasps and spiders, sting or bite when they think they are in danger or need to protect their homes.

When you get a bite or sting, some bugs inject venom into your skin. Mosquitoes leave their spit in you when they bite, causing that itchy bump. Gross, huh?

Most bug bites and stings don't hurt for very long or make you sick. But that doesn't mean they feel good. Bites and stings often make a small bump on your skin that itches, stings, swells, turns red or feels hot. If you scratch it, the bite can get red and even itchier. Sometimes bug bites can be dangerous.

Next: Bugs that bite and sting.