[lucb1e]

I know because I did a presentation on ants in high school (or was it primary school, hmm), but I'm not sure how common knowledge that is. Unless you're a biologist it's also completely irrelevant to know -- and even then, I can imagine depending on your exact job, it might still be irrelevant.

[jshevek]

I agree that the fact "legs attached to midsection" is irrelevant to most, but the implications that follow rely on principles of mechanics and biology for which I would still hope most people would have at least a basic intuitive understanding. This is an extreme example to illustrate the point: I don't know exactly how preindustrial people around the world built their homes, but whenever they used large leaves, I would expect them to orient them in the direction that best sheds water. We can make good guesses at specific facts based on principles. I would expect most people to get the ant legs correct. One might say that this bicycle sketch test proves otherwise, but there are far more unique components in the bike sketch.