Yes, knock it down for safety reason, if you think it's dangerous from getting stung, do it in the dark with a flashlight quick. They should all go somewhere else in day light,..give it a couple of days. The queen would probably start a new colony, worker bees might be joining other colonies like honey bees do, or at least live their lives as solitary bees, still helping to control pest insects and or pollinating etc.

No. All the workers die. The mated queens seek shelter elsewhere. Wind, rain and snow will destroy the nest.

I know this message is older, but wow........what a fantastic nest! I found one this summer and it looked like yours. But it always had a larger hole in it. I'm assuming it was their main entrance. But after they were gone this fall, I went up to it and saw some fur in there. I'm thinking some mice were in there. haha Its looking quite ragged now, so I don't think they still live in there......but it was out in the open. I read up on the bare-faced hornet and it sounds like they all die off in late Fall, except for the queen, who hibernates under leaves or a fallen tree trunk, etc. I think at that time she already has fertilized eggs in her. So I don't think you'll have any left-over hornets......but you never know. I had a relative who brought one in the house in late Fall and a few hornets flew out of it. But from what I understand, they don't reuse their old nest, so if you don't mind, you could just leave it up as a birdhouse! Those hornets' nests are a real work of art.

You guys got off easy ! These are THE most vicious of all bees I have encountered in my years. I ran over a nest once with a bush hog and got 26 stings all over every exposed area until finally outrunning them. They are super aggressive. I do not know their official name but I call them ground bees or yellow jackets. They typically occupy abandoned mole tunnels. Usually they get stirred up and many of them find you before you realize they are even around. Not only vicious they sting many times and keep on stinging. My solution has worked every time: pour about 1/4 pint of gasoline in the hole from a narrow neck bottle or some handy spouted container. Then toss a match onto it. The result is not what you might expect. There is a flame 6" or so high that just burns for quite a while. The vicious $%^& try to fly back in the hole and most are burned in the attempt. The ones inside never make it out. A day later none will be found. I agree with others that bug spray is useless except for 1 or 2 caught alone.