I recently bought six two week old blrw chicks so I moved my older bantam chicks into an aquarium tonight as a makeshift brooder until I can construct a larger one. immediately they began trying to walk through the glass. Repeatedly. Forcefully. I was getting nervous that they were going to hurt themselves and was rushing around trying to figure out what else I could house them in overnight when my husband walked in with a dry erase expo marker and drew lines on the glass to look like bars or wire and they stopped, walked over to the food, ate, then fell asleep. I never would have thought of it.