I have 4 chickens that are a little over a year old. They started laying at about 18 weeks and have done really well up until about 2 weeks ago. Their egg count went from 3-4/day to 1-2/day and now nothing. In April, we got 2 new chicks, who are not quite ready to lay. They have been a part of the flock for about 3 months, so nothing new there. Then in early August, we rescued a ugly little thing from a Starbucks parking lot, believe it or not! Based on her features, she seems to be about 4 or so months old. She is being treated for lice and it is mostly cleared up. She is also part of the flock. She gets picked and pecked on often. I have checked and rechecked the other gals and they have no eggs or live lice on them. I did treat them once about 5 weeks ago. Other than that, everything else seems hunky dorey. I see no evidence of eggs being consumed by the chickens, they are not laying in weird places,etc. They all appear to be healthy. Any ideas??