Cute baby squirrels! When I was growing up, we rescued a baby squirrel, too. We fed it and took care of it for a long time. It was tame when it was young, but when it grew older, it ran up a tree one day and never came back. Best possible outcome!
Their tails are fluffy, so I think they are about 6-7 weeks old. They will begin eating fruits and veggies soon in addition to their formula.
I started them on kitten formula because that's what I keep in my freezer and no stores were open. I have since bought puppy formula, because it has a higher fat content and is closer to the squirrel mom's milk.
They have been easy to handle, except one did not like the bath I gave it tonight. They eat well, and appear very healthy so far.
I plan to release them in my back yard when they are ready in a couple of months.