Any ideas on how to mark identical mice?

I have several mice who are all white and practically identical. I was wondering if you had any ideas about how to mark them to tell the difference? Maybe theres something i can use to mark their tails? Thanks!Any ideas on how to mark identical mice?
Nail polish could be poisonous to an animal if he licks or bites at it...it contains acetone. I would use food coloring! It's non toxic and stains very well. You could give them stripes, or spots! lolAny ideas on how to mark identical mice?
Put different notches in thier ears. Just a quick snip or two with the scissors. It won't hurt them any more than it hurt you to get your ears pierced. Easy, quick and permanent.
i like dave fotowerks answer thats what i did with mine but i would do it every 2 days or so cuz they clean thereselves
You can use a washable marker if it's just for a while, or you can use a permanent marker and put a number, name or symbol on their tales or feet to show who is who.Your Welcome. Always glad to help.
A black Sharpie. Do 'em up like dice.
make them seppert small collars!
My sister used food coloring on hers. It dyes their fur, isn't harmful and can be easily done again and again if it is licked off or starts to fade.
You'll got lots of suggestions on this probably, but one I've found to work on marking puppies. Is to get a lil' fingernail polish(different color for each one) and put on one or two of it's toe nails. You'd have to keep check to make sure it doesn't wear off.


But otherwise I don't know of much else.