Chiggers are terribly nasty little bugs, exteremely small(almost microscopic) that burrow under your skin, usually in areas where your clothing fits tightly(use your imagination). They cause big bumps that itch like a mother fucker, far worse that a mosquito bite or poison ivy etc.

When I was a kid I lived in Florida and would go out looking for snakes and shit in the palmetto groves, a favorite habitat of the little beasts. The first time I did I got a ton of chigger bites. I ended up scratching my balls until they bled because they itched so bad. After that I learned to use bug repellent which helped to keep them away.

Trust me, if you don't know what a chigger is you can consider yourself lucky.