I tried out the "eco carpet" and didn't think about having to feed on cardboard, I thought the carpet would be safe, but loki lost 3 teeth on the first feeding (missed the prekilled mouse, got stuck on carpet for a few seconds and pulled out the teeth freeing himself.) It bothered me so much I took out the carpet. If you end up using some type of carpet, I recommend feeding on a plate/cardboard. Just my experience.