I have quiet a few pullets that are past laying age, I have a nesting box that has 21 nest, but only 13 have bottoms, a few of the pullets will fly up on the nesting boxes and look inside at the fake eggs that are in there and they're acting really curious .. is there any certain behavior I can be looking for, that will give me a hint they're close to laying eggs? I can post pictures if need be -