Tree Seer! If I remember Correctly that was quite the nest too! I think that was the First time I had seen flying squirrels homied up in something other than a hollow or crevice.
Hearing Chip Holler when the flyers bailed reminded me of the first time I ran into a Flying Squirrel abode. I was parting out a hollow old Birch when a pair of beady little eyes popped out the top of the remaining bole and stared at me...then 2 pair, 3 pair, 4 pair
Soon I had a half dozen or so flyers running up over and around me...
I had no idea what they were cause I hadn't seen such critters before. And then they began jumping to ground! Scared me to death and worrried me sick until they popped open thier little "wings" and glided. Now that was Cool!
ThanX goodness I was in my bucket or I would have gone for a serious pole ride!
Just so nobody gets confused...I don't place Flying squirrells in the same category as "TREE RATS"