Hi I have a friend somethin seems to be goin wrong with his chickens, cut a long story short ur ha a few ponds in his smallish back garden, all his fish died 2 weeks ago for UNKNoWN reason however when he emptied his pond there was a dead rat at the bottom, we thought this is more likely cause of the death of the fish, so he cleaned and refilled pond, since then , the chicks have started getting scruffy feathers and baldy in places, all 10 chickens are girls and he's lucky if he gets 10 eggs a week of the lot of them , and last week a chucked died, again for unknown reason and again 3 day ago another died?? Any ideas of what this could be, asap help please, thanks you