We have wasps -- specifically bald-faced hornets -- dropping like flies.
If you remember, we have a large nest of bald-faced hornets on our front porch. For the entire time they've been building this condo, they've minded their business and haven't stung anyone, canine or human. Bald-faced hornets are excellent predators who control pesky fly populations (I've watched them in action, it's pretty impressive), so we left the nest alone.
This is what the nest looked like in early September.
This is what the nest looks like today. They've made this weird hook-shape near the bottom. I'm estimating the diameter is about eleven inches at its widest, and about sixteen inches from top to bottom.
But now that cold weather is here, the hornets have not been happy campers. In fact, they're dropping like flies, straight out of the nest and onto the porch and wood pile beneath.
This lady isn't dead, but she's dying.
While we're careful to make sure any firewood we bring into the house doesn't have wasps on it, once in awhile one does come into the house on a piece of wood. In here, the warmth revives them and they are capable of stinging. Not that they're acting aggressive, but it's always a possibility someone can step on one. Most of the time we just scoop them up and put them back outside.
In a couple of months when we're positive the wasps are dead, we'll take down the nest and dissect it to see what's inside (probably a bunch of dead wasps, right?). We'll do this outdoors just to be safe.
Personally I don't mind having these wasps around the house. They're beneficent insects who do an important job controlling pests. Nonetheless if they start building a new nest on the porch next spring, we'll probably spray.