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.

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.

As best as I can see from the picture, it is most likely raccoon droppings. Deer scat, although similar looking, is pelletized whereas the picture above is small seeds which is indicative to raccoon scat. Also deer scat would not be in neat little piles, it would be more spread out. As coon scat dries, it breaks apart into neat little piles as in the picture. Here, the deer scat also has much larger pellets, about 1/2 inch in diameter or larger and the droppings are not that dark.