I think I have one living in a Acer Rubrum in my yard
by Dan Howard
(Orrington, Maine)
It visits the same tree often, almost on a schedule. I can see rows of holes, but have yet to see a nesting hole. I'm not sure if it is feding and leaving, or leaving, feeding, and returning to feed it's young. It goes to the same spot each time, which is about 30' off ground on edge of woods.