DUST BATH! A chicken's favorite pastime! Totally normal and healthy, is good for keeping mites off them. A healthy chicken will dust bathe and there's nothing to be alarmed about. (It can look a bit like convulsions when you're seeing it for the first time, though
My DH thought one of my chicks was having a seizure, and when I went to check on it, it was "dust bathing" in the shavings in the brooder. The little guys operate on instinct, too!
Nope- dust baths are great for chickens. Helps keep them cool and gets rid of parasites on them. I've looked out before and thought my chickens were dead because they all dug holes and were laying in them not moving at all!