We have a small flock of 10 birds. 9 hens and 1 roo. All born this past March 2008. All have been healthy and layed great until about 2 weeks ago. Cold snap and much shorter sunlight days had me thinking that was the issue. Today my wife noticed that two hens were missing most of the feathers in their upper neck. The comb on the one brown leghorn has layed over a bit and looks a bit odd. Any thoughts? Sick? Is there some kind of mite that would cause this? Any help appreciated.