I give my rats plenty of time out of the cage so the nails are kept fairly short. Plus they have a huge 4 1/2 story cage that has plenty of room to run in and on one of the floors is kind of like slate/rock which trims the nails. I used to trim the nails & I just use cat nail trimmers and most rats have clear nails so you can see where the quick is. I also give rawhide to my rats as well as lab blocks, wood blocks, raw pasta, dog kibble & milkbones. It seems to keep their teeth short. They eat lots of hard foods too. Should you ever feel uneasy about clipping nails/teeth have your vet show you how.