Okay I have 4 Muscovies and over the last few days they are acting reallly strange, they are losing feather in their tail, breasts (except the drake). Then one hen looks like she has lost some weight. When I went to feed them this morning one hen had her down biting her. I have noticed them scratching before. I think they may have lice or something. Only thing I have is 7 dust to treat them with. Whadya think?