Chickens taken by something

A few weeks ago the new ginger chickens and some of the black ones disappeared over two days. We have some wooden eggs in the nest box to encourage the chickens to lay there and they disappeared at the same time. We are quite baffled. For the chicken we assume a fox, but it seems unlikely it would go in the house and take wooden eggs. Maybe a pine martin? We have no idea, so we have set the wildlife camera up to try to catch the culprit. So far the three remaining chickens and the cockeral are still there and we haven't caught whatever did it.

Similar time last year we lost all the little chicks to something that we think was the fox. Maybe it is the time of year that they are super hungry with cubs.