Branding hamsters

Question
Okay so I don't really want to brand my dwarf hamsters but I need a way to mark a certain one.  We have a momma and 3 babies in a cage and we are giving two of them away.  My daughter is keeping one and after she plays with them for a while she can tell which one she likes but on a quick glance we can't tell.  I am afraid when the woman comes to get the other two we may give away her favorite by mistake.  Is there anything I can use to mark it (maybe a spot of food coloring on the back) without harming it?  
Thanks for your help!

Answer
Hi Farley

It is always difficult identifying hamsters that all look alike.  The trouble with using markers is that they can be toxic.  Food colouring is OK but the hamster will wash it off.  The best way we have found to mark a hamster is to cut their fur slightly.  If you get someone to help you to hold the one you want to keep, trim off some of the fur so that it is noticeable.  You don't need to take off much - just a tuft on the head or back - just enough for you to identify it.  The fur will grow back over the next couple of weeks so this is only temporary, but by then the others would have been re-homed.

Hope this helps.

Regards