They are so cute! Perhaps you can buy another bird box and set it up elsewhere. The flying squirrels are nocturnal unlike the gray ones. I've also had so much damage from gray squirrels. They have wrecked shrubs, cut off branches and ruined an arborvitae. One removed the entire grafted portion of a Japanese maple. Bulbs and plants were dug up . We have flying squirrels but have not had a problem with them.

Those are pelagic barnacles.

Based on just the pose, it looks like an inchworm (geometrid moth caterpillar), but the photo is a little blurry. Is it spiky or furry? Is it big enough for its claws to scratch you or could the scratch have come from a trig it was sitting on when it fell that you inadvertently scratched yourself with? Can you get a better shot?

I forgot to mention that while the Nilgai is native to India, an introduced population has established itself in parts of South Texas. It would be cool to see one there, even if they aren't native.