A few weeks back (I know, I'm way behind on things as usual) I harvested the castings out of the composter. The worms seemed to have been pretty busy and things were looking ready. I cleaned out most of two bins and put half a bin worth of castings back in the new tray with the worms that I separated out.
I had plenty of castings in there and plenty of paper so I know they weren't looking for food, so near as I can tell, it was water that they were after, which is weird cause things were fairly moist at the time. Worms need to be wet in order to breathe so I'm afraid the intrepid few/many set off in search of a little something to wet their whistles. I actually felt quite badly as they had been working so hard for me and here I was dropping the ball on them.