I have one set of chicks that will be 4 weeks old this week, and our second set of chicks are due to hatch this coming Friday, with them being a month apart, when can I introduce them? Do I need to wait until they are 8 weeks or can I do it sooner? The 4 week olds will be moving into the coop this week with a heat lamp (getting cooler here during the day and pretty cold at night) to make room in the brooder for the new babies. I am wondering since they are all young can I introduce them sooner to each other or do I need to wait until they are 8 weeks old?