Bug Bots
I am thinking they might be reltivly simple to code yet could exibit complex behavior just like the batering vehicle.
Bug Bots where orignaly made in the real world by Mark Tliden. The little robots would go for hours and would even function after dammage. Then BEAM bots where inspired.
Which brings me to this. The fact is that many diffrent types of BEAM bots have been made and almost all of them have really simple circtiry, which allows them to continue to move and function even after getting dammaged. If you could encorparate this type of thing into Breve who knows what would happen. All of the diffrent type of BEAM bots could make a very in detail ecosystem and could run for months on end before finally comeing to and end.

looks cool!
Just Googled Bug Bots and they look pretty cool. Looks like it would be pretty easy to put together a demo simulation of a simple one. Why don't you give it a try and post the results here!
- jon