Here we see the tiny snail referred to by Alan Gillanders in his blog on the Fungus Beetles. These little snails come out in wet weather and graze on the surface of big leaves--at least that's where I see them. They are only a couple of millimetres in length. To discover their precise food would require some observation and, perhaps, a bit of dissection.
At the same time I noticed a group of ants gathered on the surface of a leaf. They were dismembering an earthworm. This worm was on a leaf about 1.5 m from the ground. How did it get there? Well the simplest explanation is that it must have been dropped by some other creature--a bird or lizard. I doubt that the ants had dragged it there. A less plausible explanation is that it fell from on high. I have found earthworms in epiphytes well off the ground but there were no suitable candidates for this scenario.