I've seen those used for hatching out dozens and dozens of eggs-the eggs are in the drawers, and the whole thing rolls into a huge incubator. When they hatch, they are immediately taken out of these things. At least, humane people take them out right away. It's actually a decent way to hatch chickens, since they are so wet when they come out of the eggs, and they have controlled air flow to dry. The breeders know exactly when they hatch. I would NEVER keep anything in there as a cage! Evil person for suggesting it! >(