Greetings! We moved our 6 chix (now almost 4 weeks old) out into their new coop a few days ago. I am still leaving the heat lamp on all night, into late morning until it seems to warm up outside. The overnight lows look like anywhere from 40F to 60F over the next week (one night down to 35). My question is, When will I know it is warm enough and they are big enough that they don't need the heat lamp? It was so warm tonight when I went out to turn it on (about 8pm) and they were all snuggled up in a corner (making sleepy little chirps) when I came out... I don't want the light to keep them up and active when they should be sleeping, I don't want them to get too hot, and I don't want them to catch a chill! How will I know? What are some guidelines for turning off the lamp?? Thanks!