How many Watts before a swat?

January 11, 2012 6:52 AM

How is it that a tiny housefly has enough energy to drive me mad by flying around my house for an hour or more? How long could it keep going?
posted by rongorongo to Science & Nature (2 answers total)

Flies are much, much smaller than birds, who can sustain flight for hours. The weight of an animal goes roughly as the cube of the length, while the surface area of the wings goes as the square. The fly therefore has big, efficient wings and doesn't need to expend as much energy per gram of body mass to keep itself airborne. The only saving grace is that they have a lifespan of seven days!
posted by wnissen at 7:08 AM on January 11, 2012 [4 favorites]

Well, presumably it's not flying around 100% of the time -- though it might seem like it. Sometimes it's stopped, and at least some of that time it's probably eating. So it's not only expending energy, but also taking it in. They can eat practically any sort of sugary residue or substance, as long as it is water-soluble.

Combined with the very efficient wings that wnissen mentions, there's probably more than enough food around in your house to keep a single fly going for its (admittedly short) lifespan.
posted by Kadin2048 at 9:00 AM on January 11, 2012