Gerbils made quick work of chewing RIGHT through every single piece of plastic on this item.  I should have gone with my gut and just gotten the boring old glass aquarium, but I wanted something "Cute", and thought they needed toys and gizmos in their habitat.  They don't. They want to burrow and chew and that's their life.  Save yourself a ton of money and hassle and go with a metal/glass aquarium, or you'll be spending $200-$300 on replacement cages within a few months or less.