Hi my 3 hens have all stopped laying. One laid all winter but now coming into summer they have all stopped. They are all abt 2-3 yrs old and laid every day last summer.., the Banty was laying but now has stopped and now sitting on nesting box on nothing! We have had crows and magpies abt recently and not sure how to deal with that As coop area is a corner of garden and not covered . I've treated them for worms and don't see Any red mites... ? Suggestions pls?