Marking rats

does anyone have any safe suggetions for marking rats, you know sharpie,dye,ect. I used a sharpie on a pain in the a#$ females tail that I really dont care about(baby eater). In the future though I should probably use something safer:D.........sometime I find you need to know whos who with very similar looking ratties.........that is all:D

have you thought about ear clipping? we used to use that method on the mice colonies (back when that's all that we bred).

cherry kool aid.

I clipped ears on some at one point. I also used colored nail polish on the heads once.. and food coloring once. The ear clipping worked most permanently. If you can get a decent blob of nail polish on the head, it works a little while. Sharpie didn't seem to stay and the food coloring was washed off fairly quickly.

all good ideas, so far the red sharpie is on their tail pretty good:gj: