I'm starting to get a little worried about two of my hens. One of them is an almost 2 year old Cochin bantam, and the other is an almost 1 year old D'Uccle. Neither of them is laying any eggs. The cochin laid a lot last year, and then stopped when she started molting. The D'Uccle laid one egg (her first) in winter, and then stopped when it got very cold. But all my other girls, including my other D'Uccle (same age), are laying as usual again. What I'm concerning though, is that I have seen them go and sit in the nest boxes several times throughout the last month, as if they were going to lay. But then they never did. They look and act fine, so I don't know what's causing them not to lay. Do I just have to wait longer, or is something wrong?