I have a small flock of six hens. The three older ones (only a month older) are laying and have pretty good production. The three younger ones are 23 weeks and they have red faces but have not yet laid. It has been in the 80's and 90's and very humid. I have seen that the three older ones are very protective of the food. I try to put out multiple feeders to make sure the younger ones are able to get enough feed. Is there any reason why the younger ones have started to lay yet?