You know how you're laying in bed sometimes and the lower part of your leg starts itching? You try to ignore it, but it just keeps itching, so you try to rub it with your toe. That stops it for a second, then it comes back, and you swear it's worse than before you rubbed it. Pretty soon it's all you can think about. You can't get to sleep because the little itch on your leg has gotten in your head, and your skin is starting to crawl. Sometimes you just have to throw back the covers and scratch it