I have a group of girls that are 18 weeks today. They have plenty of water and feed available all the time. They get a little treat of scratch in the morning. They have been on layer for 1.5 weeks and I put a 40 watt white light out about 5 days ago to give them 13 hours of light. We run around 34 degrees for the high and 20's for the low. They seem happy enough. Is there anything else I can do to get them to start laying?