Normally I'll use a few zerobot veggies with point mutations set to 1 to rapidly generate the initial dna. After the useful dna builds up, I keep an eye out for any bots that develop shooting or feeding and then change point mutations to the default to make sure the trait doesn't go away.
I'll start them out as normal bots, with a few veggies providing nrg via sharenrg/ties and reproduction via memshots. Brownian motion is set to high and the sim is torroidal to help them initially find food. After awhile I'll reduce the amount of brownian motion and encourage the evolution of normal movement.
I've taken to using another bot to force the zerobots to produce "viruses" to duplicate useful dna. Have to be careful to avoid cross contamination, but it can considerably speed up evolution. I used it once with my own bot to duplicate it's movement dna, letting me ween them off sharefeeding. I used it again to mix one of Ikke's zerobot's reproductive dna and my zerobot's, letting them self reproduce.
Currently trying to slowly raise costs for them, they're operating under near F1 conditions with a veggie similar to Alga_Minimalis for food.
Not sure why you're getting overflow errors, haven't had any myself for awhile.
Heh, mine have done exactly the same, they just all tie-up in one big webbed swarming mass as they munch though a field of veggies and then when they are done, as they die back some break-away and scatter to find more food. A few come across a new patch and it starts over
Are your bots actually moving by themselves? I've noticed alot of the bots tend to over-rely on ties and veggies for motion and don't go searching for food themselves.