I have two roosters who act as though their equilibrium is out of whack. They twitch, wobble, act disoriented, etc. All of my other chickens that are housed with them appear normal. They're still eating and drinking, but I'm concerned about them. One of them is a 4 month old Silver Polish and the other is a 2 month old Black Cooper Marans. Could someone please tell me what is wrong with them and how to cure it? Thanks for any help!