I came across this incredibly cool proteobacterium while reading up on genomic work. M. Xanthus changes its behavior from single bugs to "swarms" depending on food conditions, so people are looking at which genes are active during which behavior.
But I couldn't get over this organism. Starving M. Xanthus , like all Myxococci, will gather together into a fruiting body of about 100,000 individuals (a movie is available at the link). But M. Xanthus can also behave as a predatory swarm, which can glide across surfaces (more movies). During swarming, the colony starts to secrete all sorts of antimicobial substances which help with predation.
Sometimes individuals break off from the swarm in so-called adventurous motility. (social motility involves contractile ripples within the aggregate). Adventurous motility is accomplished-- I'm not making this up-- by a slime rocket. The working model is that slime accumulates inside the nozzle; gets wetted from outside, and the force of swelling expels the slime, providing propulsion.
Taken from Wolgemuth et al., Curr Biol 12:369 (2002).
Wow, see what I missed by taking neuroscience?