D: Today, on A Moment of Science, we're reporting from the top of a skyscraper in an      attempt to leave behind those pesky houseflies. [FLY BUZZING]

D: Uh oh, what's that? [SWAT]

D: Geez, I just don't understand it, Yael. Here we are, over a thousand feet up, and we      still need to bring a flyswatter.

Y: Well, it is a pretty warm day out, Don.

D: So? What does the weather have to do with anything?

Y: Well, most insects can fly as long as they are in air that's about fifty degrees      Fahrenheit, or warmer. So, if air temperature at ground level is about seventy      degrees, insects have about thirty-six hundred feet before they hit the ceiling, so to      speak, and it's too cold. On ninety-degree days, that border is at about six thousand      feet.

D: So there's no getting away from them, huh?

Y: Nope. In fact, insects will seek out their ideal temperature for flying. If they reach a      height where it's too cold for them to fly, they simply fold their wings in and drop until      they reach a more comfortable cruising altitude. And here's another interesting tidbit:      insects that migrate long distances hitch rides on the fast winds that move in front of      storm fronts and then glide along, which ends up being more energy efficient than      flapping their wings. And air moves fastest at about two and half times the height of      the largest obstruction around. So if we're on a thousand-foot skyscraper, the fastest      air is moving about us at about twenty-five hundred feet.

D: So you mean there are insects zooming over our heads as we speak? Ugh!

Y: Oh, Don, get over it.  

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