My chicks are about 1.5 wks old and Im thinking it might be time to move them to a new brooder (bath tub). I just got them on pine shavings which they love, and raised the water dish which is working well. However my two australorps feel like its fun to dive bomb off of the Brinsea brooder and they have even figured out they can hop onto the top black part and try to fly out. Now I have to always have the cover on or at least on over the Brinsea so they dont try to jump out. Would this be my sign? My other two, EE and a marans havent seemed too interested in being dare devils, the EE likes to get up there but my shy little marans couldnt really care less. They dont seem to be picking on each other except for the exploratory pecking that a baby might do. Im concerned that they may freak out when they have so much more space? The tub doesnt have a lid system, but it does have sliding doors (step in tub), would this work?