question for rehabber friends

[gwsgrand]

I got in three baby grays yeasterday who are all girls and just at one week old best I can tell. My question is they poop really good and have taken well to the new formula that I use for all flyers and grays. But they are not peeing. One did last night and I was so happy.
They are eating really good but how many times do you feed a 1 to 2 week old gray? They look great and don't look like they are dehydrated (SP) Do you think they are peeing in the bed I have them in ? I am changing it today. It is getting to where I can really smell it. I am open to all suggestions. I am afraid to keep rubbing their little bottoms to much for they will get raw. LOL Also is it ok to put a magic marker mark on two of them in different colors so I can tell them apart? if so where and will it come off later? Thanks for your time
Gail

[violetlady]

Gail, while I've not raised grays that young, I have other critters, & found that some tend to stimulate themselves while scooting around on the bedding. I would simply stimulate briefly after feeding using a Q-tip or cotton ball. If they don't pee right away but otherwise appear okay, I'd just move on to the next care step. I have used both water-soluable markers & food coloring (Q-tip to apply) as id tools. If the fur is a light enough color, I prefer the top of the head. In the cases of dark or black colors, the tummy is about the only option (sometimes underside of neck) & has to be reapplied often.