I remember once in way back land when I taught large (150+) classes of biology for non-biology students at Kent State University that I tried to bring up the major themes in biology and ecology and nature in general. Then I would use those as a unifying themes throughout the course. Pointing out whenever I could how this was one of those concepts again. One of those was balance, and how it seems that whenever something gets out of balance in one direction or the other, nature's integrated systems would tend to bring things back to some steady state or balance. It's amazing how that works both at the micro (biochemical) and macro (ecosystem) levels and everywhere in between.
I bring up this archetypal concept because I saw this really neat balancing act on Funny or Die today that I've never ever seen before: