they are adorable! love your brooder! I also have used a dog playpen as an intermediate and “run” during transition to coop. chicks can escape (squeeze) through the bars up to 6 weeks in age depending on the breed. my only recommendation would be to consider the vitamin electrolytes in water due to the high temps and also layer of paper towels over shavings the first few days to deter eating the shavings. (it also makes for easy changes!)
