"Bees" and Pokeweed
At some point, the hole in the tree stopped being a home for cute squirrels and became a home for slightly less cute hornets. I called Orkin and they sent out, I swear, one of the Ghostbusters; a 6 foot tall Amazon in white coveralls who said, with some regret, that "they didn't do trees" and she thought they were wild bees. They are small and so far not super aggressive--here you can see a woodpecker working right next to the hole, and the workers are keeping an eye on the bird. The hornets did hover close enough to make the woodpecker flap, but the bird just moved up a couple of feet away from the hole and went back to eating. This is the best photo by far I have been able to get of the hornets; that bright yellow abdomen makes me pretty sure that is what they are. I would leave them alone, except they are close to the front door, and there is a ton of room inside that 40 foot tree for a really epic hornet home, so I may make some more calls to see if anyone will...