Re: New to pinkies..
Unfortunately I do not have experience with pinkies, but perhaps they are getting too much formula per feeding? Everything I have read recommends starting at 5% of their body weight (in grams) per feeding which would be right around 2ml each. I also think I read somewhere (wish I could remember the source) that sometimes baby squirrels take formula better if they are stimulated to pee/poop before feeding as opposed to after. Wish I had more personal experience that I could offer. They are adorable by the way!
“Some people talk to animals. Not many listen though. That's the problem.” -A.A Milne