Some people say they do... but if you take them anywhere/are shoulder training them, they'll need the nails to hang on! I don't trim mine, never have.
i trim mine occasionally though not very short (like erinsweeney says they need some nails to cling on). mainly i do it for shows but also if they meet the public or if they ates old and not able to keep them to a safe length themselves. I've done this for many years and only over cut twice, the rats were less bothered than me lol. i also regularly do other people's rats at shows. at the last one i had about 10 or 11 queing up for me lol.
The trick is to stay calm, take your time and only cut when the rats settled and you've got a firm hold on them. Also pick what you use. i prefer sharp nail scissors as i can see better than nail clippers bit you have to be very careful to keep the point away from the rats. i dislike cat or dog nail clippers they are just to big for rats.
Thanks!I put a lava ledge under their water bottle. Each time they drink, they step on the lava ledge. It saves me the trouble of calming down the babes. If your concern is the sharpness, this may be a useful solution.