I feel really silly asking this question. I know that I'm supposed to lower the temp by about 5 degree per week. I do realize that's a guideline, and I know to judge it mainly on their behavior. They are now 35 days old. I've given up on the thermometer and keep backing the light further and further away, but at what point can I just shut it off? I'm in NH and the temps can vary from high 60's - 80's, but we're typically in the 70's each day. The chicks seem to change their preference by mood. Sometimes they'll sleep at the shady end and sometimes at the lighted end. In between naps they mull around all over the brooder. My father came to visit last night and is wondering why I still have it on at all, but he hasn't raised chicks in 20 or more years. So when can I shut the light off?