I too am very allergic to bee/wasp stings and was freaked out 2 years ago when in the fall, after the leaves had fallen, I saw a bald face hornets nest about 6-ft off the ground in an ornamental pear tree I spent the entire summer mowing under. It had to be a foot across easily.
I find bees are far less aggressive than wasps, maybe because they know when they commit to sting you they will die (they have barbed stingers) while a wasp can sting you as often as it wants without it suffering any harm (unless you hit it) because its stinger is smooth.