I use something that size for little chicks on heat - I actually have a dog cage but now I've seen that, I'm tempted because it looks more cat proof. By the time they're two or three weeks, they're generally too big for it and need more space to run around. Maybe they'd last a little longer with bantams and I guess it depends how many you have but you might need another interim step before they go outside. But certainly a good plan for newly hatched chicks.