I have 4 hens who are just now about 20 weeks old. They include a Jersey Giant, Black Sex-Link, RIR, and Golden Comet. They have all filled out very nicely, and have red crops, faces, and combs. I thought I remember reading somewhere that sometimes, if they hit laying age during the shorter days, they won't lay at all and completely skip winter before starting to lay for the first time in spring. What are the chances this will happen with all 4 of them?