I have an 18mo old cuckoo marans who's plucked her belly totally clean, isn't laying, but isn't broody. She sits in the nest box every other day or so, but doesn't lay anything. She leaves the box after an hour or so. Checked for mites/lice etc, but found nothing. Haven't see anyone plucking her. . . Any thoughts? Separate her? She's been this way for about 2 months. She eats and acts just fine. thanks.