I suspected one of mine was eating eggs, but could never prove it. I split them into two groups and waited - got eggs from one group so split the other group again, got eggs again so was able to identify the culprit. But it might just be the weather and light. AFter all eggs are babies and they are hatched in 3 weeks so would it be warm enough then for chicks to survive if your hens hatched them?? Nope
Maybe they don't logically think that way but their body clocks might