We use these in our play areas and they work great! We have since gotten rid of the bottom of the box and just use the dome lid. We put fleece blankets on the floor and place the lid over the blankets. The ferrets love to go in their nice, dark cave for a nap. Ferret hugs, Kathy Ferret Nook Shelter / Adoption Center www.ferretnook.org International Ferret Congress www.ferretcongress.org www.kritterkoncepts.net/store [Posted in FML 6321]