Traveling around America, I've noticed fewer mosquitoes in Portland than most other urban areas. Is it the climate? Secret nighttime spraying? Or just hungry salmon? —Forrest

Here's the thing: If Portland is light on mosquitoes, I know why. But I can't prove that it is.

Anecdotally, I'm with you—I grew up in the muggy Mississippi Valley, and I recall the mosquitoes there as basically the bugs from Starship Troopers, only with wings. They darkened the sky of a summer's evening, strafing our villages and carrying off children and livestock, and to my mind, the Portland version has nothing on their size and numbers.

Unfortunately, science doesn't have my back. A statement from Multnomah County Vector Control gives the party line: "Our geography as a flood plain and our proximity to multiple bodies of water contribute to the large presence of mosquitoes in this area," they claim. "We have just as many mosquitoes as many other urban hubs around North America."

Hmm. I don't wanna be the guy that says that since it snowed last winter, global warming must be a hoax. But…really?

"My guess would be that there's no way to tell," says Matt Davis of county vector control. "It becomes really difficult to compare one city to the next in terms of mosquitoes, because there are so many variables involved."

Once again, science's obsession with "evidence" and "facts" lets us down: We don't know. Just channel your inner Republican and believe whatever you find convenient.

If we are relatively mosquito-free, though, it's probably because Portland summers are dry, so we don't have the standing puddles they get in, say, the Midwest, where there's a thunderstorm practically every afternoon. No puddles means no place for mosquitoes to breed, and better picnics for all.