Hello, i am new here.. I bought 25 wellsummer chicks ( females ) from stromberg nursery. They all arrived healthy and chirping. They are doing great, I built a brooder box (wire and wood) and keep them warm 70 - 80 degrees.. when should I take them out of the brooder and let them go free in the chicken house? I have let them out on the ground twice for a few minutes, they seem to prefer the brooder box.