I have two sex-links that were given to me by my sister 3 months ago because she had too many. They are around 6 months old and are not laying. This alone would not concern me except that all of my sisters hens from the same batch have been laying now for weeks. This leads me to believe I'm doing something wrong. They free range in my backyard and I daily do a yard search to see if they're laying outside their nesting boxes, but find nothing. They have plenty of water, are healthy, and have been recently wormed. I have had them on starter/grower til a week ago I started mixing half with layer feed. I'm stumped on why they won't lay. They seem to be happy and healthy girls. What am I doing wrong?