I live in Choctaw, Oklahoma. They are almost 4 weeks old. I put a light in with them the first 3 1/2 weeks but it is in the high 70's at night and the high 90's to low 100's during the day now. I was worried the first night I left them without a light but they huddled together and did fine. They have been sleeping without their warm night light for about 5 days now and all are thriving. I transfer them to a wire cage which has ground access during the day and back into the brooder at night. They love to eat grass and are going through much more feed now. Started with 16 and still have them all. I love my chicks and spend way too much time just watching their antics.