stated, could have very well been a carpenter bee. Looks like a big bumble bee without the yellow stripes on the rear of the body. They will drill a perfect 3/8 inch hole in wood almost fast and neat as you can with a drill. Damn things have eaten my barn up.
Although I've seen some huge black, what looked like hornets(don't know their correct name) with bodies up to an inch long while out hunting. No yellow on them. All black.