I have about 40 batams in a 20 x 20 pen. I started out with about 15 batams and then my son hatched some more and put in with my other batams when they got bigger. We also have some silkies in with the batams. We started to notice that quite a few of the batams are blind and their tails are going to the side (on the roosters). We have saw dust mixed with dirt/sand and we have gotten a lot of rain these past few months too. Any ideas of what is going on and how to treat all the birds in this pen?