MedlerFarm16
In the Brooder
hmmm
Maybe gases as R2Elk said, I think heat. I raise mine in a 4ft by 8ft pen with hardware cloth on the sides. I do set the temp at 95 for the first few days, but they spent a lot of time at the far end of the pen also. That is 7 ft from the heat source. Also that is in April and May when nights are cold. 95 seems high for this time of year. But I do not know your climate.
I am thinking the tote was just not big enough to let them get away from the heat. Also a tote has no ventilation on the sides so heat is trap, bad gases are trapped. I am just not a fan of totes.
Their inside my house!!! An lid isn't on it, so nothing is trapped!!!!