Dust bunnies

When you blow out a candle, the air moves fastest and strongest close to your mouth, but farther away the puff fans out and, because it is pushing a bigger volume of air, weakens and dissipates. So you have no problem extinguishing a candle from a foot away, but across the table the flame hardly flickers.

I am informed that most household dust is not tracked in (though the front hallway testifies to the contrary), but is made of dead skin cells that flake off and dry out and are carried by the breeze, or the detritus left by the mites that eat the cells. They are small enough that some are able to sift through the weave of the fabric in the sheets and mattress fabric, and collect under the bed. Since we spend about a third of our time in bed, I'd expect that under the bed would be the most concentrated collection of dust--but it seems not to be so. Perhaps because we don't move so much, and don't rub off so much dead skin when snoring as when walking about. Or perhaps a lot of dead cells accumulate, stuck by residual oils to the mattress stuffing. Pillows get heavier with age, perhaps mattresses do too.

What seems completely unintuitive is the accumulation under dressers. Things can't fall through the wood. Probably dust, once it hits a collection, tends to stick. Then as the airborne dust whirls through the air some puff of breeze from passing feet will push it under the dresser. Of course the air pushed in will have to push other air out, but thanks to the dissipation I mentioned in the first paragraph, that will be weaker. Once under there, dust is more likely to fall undisturbed and clump.

Which seems a plausible reason for why the dust bunnies look like Harvey.

On the other hand Dave Barry claimed that men are biologically incapable of seeing dirt until it accumulates in quantities sufficient to sustain agriculture.

Pick your reason.