JKMB wrote:
Could be a programming error
Or it could be "storage day".. but I dont see why they would run repeatedly back and forth in that case..
I would say probably they are teleporting back to town with a full inventory, storing it, repairing equip, buying pots, and going back out to grind. As someone above mentioned, these bots are probably being killed by a bot trap.
The back and forth is probably them emptying storage when it gets full to NPC everything.