I have 4 red layers about 2.5 years old. One has been lethargic for the last week. See stays by herself under cover most times and does not socialize with the others much. Seems to be drawn in with head and wings and legs tucked in. Appears to eat with the rest from what I can tell. Last two nights did not roost but balled up in the shavings or tonight sat in the laying box. Can't feel anything to suggest eggbound but have her in warm water now and will keep inside tonight in the warmth. One other thing is poisoning. Had mice in the nearby shed and baited them with a commercial trap. Saw two run out while yard working and one was eaten by the hen, likely this one. I removed the traps when I saw that and read here that the poison should not harm the chicken unless it was a lot. Could it be the poison did not kill her but disabled her in some way? Egg production is down heading into winter but up until last month was getting 3 per day. Any thoughts or suggestions?