Honey Bees, (not the africanized ones) are really quite harmless and beneficial. And unless you are alergic to them, there sting is only a minor irritant.
Wasps are the most evil looking things, and they do sting. But their sting is only mildly worse than a Bee, and they are also very beneficial as they do take care of SPIDERS (note for Mano) and other insects.
Bumblebees are a freak of nature. They are not supposed to be able to fly, yet do. They build nests in rotting wood, and generally leave you alone, unless like me, you try to catch them. Their sting, while their appearance would indicate otherwise, is very wimpy.
Hornets are nasty mean rotten bastards! They exist for no other reason than to harrass you and sting the shit out of you! Their stings feel like someone sticking a hot poker on you! Unlike Honey Bees, they do not loose their stinger after stinging, and they gang up on you! These things are an abomination from hell! A pure devil spawn!
The last is what you probably had. Wasps build paper and mud nests (depending upon the species), bees live in hives (they enter and exit by the same means), Bumble bees dont care for dry wall. But Hornets will build nests anywhere and are too stupid to figure out how they got in in the first place. They look like Honey bees, but are not fuzzy. They are to be erradicated whereever they are found, or they will spread their venom with a diabolical glee!
How do I know all this? I have been stung by all of them. But only the Hornets swarmed me (twice) and damn near sent me to the hospital with over 2 dozen stings each time! (I am not allergic to any of them).
As far as I know, Hornets serve no useful purpose and are so Eeeeeevvvvvvil that they live to harrass humans. Nothing more, nothing less.