I have two backyard chickens that come to the back door every morning. this morning both were at the back door but the hen was falling asleep and dropping her head. upon closer inspection her feathers were ruffled up and it looked like something had slobered on her neck buy there was no blood or cuts. I continued till watch her all day... she would follow the roster some what but was still very lethargic. I just checked the hen house and she is not on the perch like she is every night to sleep but in her nesting box instead. also of note she has only laid one egg the last five days but it has started getting colder here the last week or so..... any thoughts?