They cause staining on the outside of your house when their toilet is in your soffits, it looks like a brown liquid running down the siding of your house. they will fill up the area and then move to another spot a few inches or feet away and fill up another area, heavily infested Flying Squirrel toilets can make the siding and areas almost black.
They can fit through a hole the size of your thumbnail and can squeeze through a linear crack the size of your pinky finger. Flying squirrels are omnivorous and will eat acorns, fruits, seeds also mice, bats, small birds, bird eggs and have been observed eating their own species from a different colony. They love to devour bee, hornet and wasp nests and eat the larvae.