I have a three year old black rock hen who is acting very differently than usual.for the last few days she has stopped laying, she sits in the nesting box for up to 6 hours at a time, she has stopped eating although she drinks. she seems very lethargic like she cant be bothered to do anything. she is normally very vocal but this has stopped too. she looks quite normal, her crown and wattle are a nice red. could she be eggbound? she is normally a very regular layer.