Before you read this suggestion read: (http://forum.darwinbots.com/index.php/topic,6654.0.html
So to expand on the bot enviroments, the addition of saturation (water levels) and then, to veggies (Because veggies are SOOOOOOO underworked) roots.
Realistically, roots are more important than any leaves to any non-animal/non-bacteria/non-virus/non-parasite because it gets nutrients from it...which is pretty important!
Roots would be in essence, ties (maybe not straight though) with nothing attached to the other end...and it can consume nutrients from around the roots, if it didn't have roots, then it'd consume the nutrients from just around the bot...(Yes, these suggestions im doing are making NRG more complicated, and not just godly energy NRG and toxic nobodyknows waste.) Then, possibly leaves which will show up semi-transparent, and do the same as roots, but for the suns energy (and loose moisture at the same time)
Several ways of turning, sun & minerals & food matter into energy...just thrown into the DNA (of course when I say several, there would be hundreds of ways with a few more sysvars to implement this, but some would be listed on a basic tutorial...so digestion, photosynthesis, mineral decomposition...) (Veggies eating corpses, or other veggies would be digestion)