Nutritional Value of Tree Bark

[dda0221]

My two fox squirrel boys (about eight weeks old) would prefer to eat bark over their rodent blocks. They do nibble on the block from time to time, but most often eat the bark. I put some branches in the cage so they would have something to climb on. The branches are from a plum tree, fir tree and a maple tree (yes, all pesticide free).
Do I need to remove all the branches until I convince the boys to eat more rodent block? Are they getting necessary vitamins from the bark?

[dda0221]

I am feeding them Mazuri, which they will eat, at least a bit, if I hand it to them or hold it for them. They can hold their own food.
I am also feeding them formula, about 13cc, four times a day. I believe I should knock it back to three times a day this week, which might kick start their interest in solid foods.