So why post a photo of a leech?
Bear with me. If you can get past the unpleasant natural history of this particular leech – I think you might agree that it is at minimum "interesting looking". In fact, I think the pattern is quite remarkable.
I have been to part of Asia where terrestrial leeches find their way into your clothing, into your bed, and into the shower. I watched one leech wriggle its way through the eyelet of my boot once, and I knew that later, when I removed my boot, there would be an ugly brown leech engorged with blood stuck on my foot. Believe me, i'm no fan.
But I can appreciate a successful evolutionary strategy when I see one.
aquatic leech in various stages of locomotion