Lamebots are bots that lost the ability to move.
This allows for the creation of large groups of co-existing bots since nrg is being directed primarily towards reproduction and hunting. Since the bots are always in the same place, returned energy shots are always guaranteed to return to the shooter. This solves part of the problem of "sloppy eating".
Unfortunately this is not always a beneficial mutation. Along with the danger from Cannibots, these bots must have food move within range or be moved to the food. The typical Veggy Repop will allow a stable population to thrive provided enough of them exist or if the food is being eaten by mobile bots at another location.
Eventually, however, it is possible for food to respawn out of range, and the bots will slowly die off.
A modified form of these are semi-fixed bots. These are bots that rely on temporarily fixing themselves then either randomly or situationally unfixing themselves. This allows them to have some mobility, while maintaining a close group of bots most useful for entrapping food in The Pit sims or Flying sims.