Leeches have also been in the news lately, as a recent paper has demonstrated their utility in monitoring mammal species in dense forests. This is one more valuable tool in the often desperate field of conservation biology.
I have embedded a video of the leech looping its way across the moss. It's pretty blurry, but if you look at the left hand side of the screen between 2 and 5 seconds, you can see a cool little mite or something scurry along and then disappearing into a crack. These miniature forests and their inhabitants are so fascinating.