Lina - what kind of rock? what I mean is, did you just pick a rock from somewhere outside? or did you buy a special one from a pet store? and if you just picked a rock from outside, what did you wash it with? just soap and water??lina said:Have you tryed putting a small rock in her cage. Every time she runs over it or jumps onto it it will file her nails down. I do it with all 6 of my rats and none of their claws have over grown. Just put it in a place they will use a lot.