Why are my worms collecting at the bottom of my bin?
I have a question to vermicoposters who have multi-tier bins (please, only multi-tier bin users...this will really help me). I have a bin that is currently three tiers. I've noticed that whether or not I reduce the bin to one tier, or to three/four tiers, the worms consistently travel down to the sump tray which contains fluids and mucky compost that they seem to feed on over and over again. They just hang out there, even though the above bins are perfectly dry. It seems they're even breeding there and there are even baby worms in the wet sump tray.
I cleaned a bin out a month ago and went to check on the sump today and sure enough, there were tons of worms down there, even though the sump tray itself wasn't very wet at that point. I'd like to know why they like to collect there?
The conditions in my bins seem to be stable. There was a bad smell in one of the sump trays. The others smell just fine and weren't very wet. Still, ALL of the sumps, including the smelly ones, had worms everywhere, collecting.
If you're a multi-tier bin user who has experienced the same or know why they keep traveling to the bottom of my bin, can you please let me know?
Thank you all.