They sound like carpenter bees you could google your state for black bee types to find out what type they are if you'd like know for sure. Your county extension office probably has info, too.
Around here they swarm (split hives) mostly in spring and fall, and I've had to high-tail it inside a few times to avoid them after hearing that roar coming and seeing them almost right on top of you.
I hope they were the basically non stinging type and hope your buns are ok.
In some states like Florida where I am, if you hire a Bee Pro to remove Bee's by LAW they are supposed to kill them, if you live in a state that has been proven to have Africanized Bee's they probably have the same law.
But I agree if they are all black they are probably Carpenter Bee's. Really harmless as with almost all Bee's if your not wearing a strong perfume or after shave or don't start swatting them, you can also ramp them up by killing one, it puts off a smell that other Bee's pick up that tells them to protect the hive.
Could they possibly be paper wasps? They like to build their nests in wooden corners. We also have problems with them nesting in the eaves of our home.
Without you posting a picture we're just really guessing...
I feel your pain...right now I'm battling wasps, yellow jackets AND bumble bees in my barns!! The goal is to eliminate the wasps and yellow jackets and get the bumble bees to move...right now they are winning...
well i have really no idea what they where,but they are gone! i was telling my neighbor, she told me that there had also been a bunch of bees at her house that day. comparing what we saw,im sure they where the same thing. my bees where on the hutches,grouping on the legs that had pee,hers where on the leg of her porch where her little dog like to pee! idk but it was weird! no bunnies where harmed!!