COEUR d'ALENE - They're back, they're mating like mad, and there's not a thing you can do about it.

An annual autumn tradition as dependable as any other, aphid flies have returned to clog Coeur d'Alene's air. When school starts and the leaves turn, it's also the time of year to start waving your arms in front of your face.

The good news is, other than annoying folks, aphid flies don't do any damage. The bad news: other than staying inside, there's really nothing that can be done.

Soap? Pesticides?

Don't bother, said Dorothy Kienke, master gardener program coordinator with the University of Idaho extension.

"You're not going to make a dent in them," she said of taking an aggressive approach to combat them.

Rather?

"Just be patient," she said. "They're not doing any damage."

For around 10 more days, that is. That's when Coeur d'Alene should see a steady pattern of freezing temperatures at night, according to Cliff Harris, regional climatologist. Cold weather being the only thing that kills the blue bugs off.

In the meantime, they're feasting on sap, hanging around tree trunks and bodies of water like the lake where it's not as cold as other parts of the region, and mating in the air.

Yes, that's exactly what they're doing.

"The dance of love, I guess you'd call it," Kienke said.

But so routine is their autumn arrival, locals say it's a part of the region, like snow in the winter and boaters in the summer.

"I just walk right through them, there's nothing else to do," said Jill Buckland, sticking to her walking return in City Park Wednesday despite the pockets of blue aphids clustered in the air. "I'm not changing my life for them!"

It could be worse.

So said Ron Dorn, another walker braving the elements Wednesday, who used to live in northern Maine where black flies would swarm the region annually and bite people, as well as southeast Colorado where clouds of moths were the norm. So aphids are a regional staple, he said, and not that bad of one all things considered.

Of course, that's not to say they're a pleasure to have around.

"I'm going to start doing it with my hat instead of my hand," he said of his waving technique.