We had always had hand raised regular Norway rats when my children were small. Although those rats were sweet and active, they were messy and chewed anything that got near their cage (including the sleeve of my son's jacket that… More was hung too close and the carpet on my stairs that was close when the table got pushed over near the stairs) Last fall, we bought a pair of dumbos and were really happy with them What surprised us was how clean the Dumbos are comparatively, how they don't poop or pee while you are holding them and how they don't chew up everything. We bought the little hammock beds and our old rats would have chewed that up quickly. These rats use the hammocks for sleeping and neither destroy them nor poop in them. They use a corner of the cage for a bathroom and are really clean. Their mom taught them well!!