Or better yet, what if we made the waste 'stink' if you will? This would mean bots could smell waste shots, and once it entered their field of smell, a bot could start recieving information about what kinds of bots are in the area. A single turd could allow a predator to determine the next best move. Or the turd could be used to warn friends faster than info shots or in/out, sense smell is really sort of 360 in effect.
I say we place the field of smell between the field of vision, to 50% beyond whatever the eyelength is set to. This would mean if a bot wanted to have long range vision, this 5th sensor could be used to continue to watch itself. This also means that if the eyes are overdevloped and reach 360 vision, the bot will have lower field of smell. This takes out the problem of new shot types, and programming for them, and also allows for bot identification to occur. Still, if the Refvals can be shown through a turd, it should really be limited to just a few pieces of information per turd, and should be radnom for each turd. That would mean that a full-spectrum analysis must be done to find any dna, or each refval would have to be checked to see if it exsists in the turd.