Hmm, one way is to make "dirt" just another substance on e-grid. We were thinking about "absorb" commands that would grab a portion of stuff from the current square and place it in the stomach. These commands would be either very specific, addressing a particular layer of env.grid (say, to absorb only glucose) or very general, where a bot would just grab a piece of "whatever is out there". Then the bot could digest whatever it can and dump out "waste". So bots would run out, "absorb" dirt, run back and "waste" it out.
Or we can make special rules for dirt. Right now I am OK either way.
Maybe special rules is better, because dirt "will" be special - it will have characteristics that distinguish it from all other substances on env.grid, right?
P.S: 2.36.5 runs fine for me for 3 hours already. It is just 600,000 cycles (becuuse I am running size 12 with > 300 bots), but so far not probs.