Super Pet Keep-A-Critter Small Pet Home or Carrier www.petsmart.com - $6.99 (small) Product Description: Can be used as a temporary home, nursery, or a safe small pet carrier. Remove the pop-out water bottle opening on top and slide in a Super Pet Crittertrail mini water bottle. RattyRat's Review: If used properly, these plastic aquariums work well as a transport cage, even protecting your animals from the cold better. Here is the problem we have with these carriers. We have heard more than one story of a person carrying this carrier home by the handle, only to find that the lid wasn't on right, and the whole base crashes to the floor. The rats can get hurt from the fall, not to mention being very frightened to the point where they run away in panic. We know many people who have lost there rats this way, many out in parking lots and on the streets. We don't find this carrier to be very safe.