Bacteria: They don't think, but something in them thinks
In "Why microbes are smarter than you thought," Michael Marshall at New Scientist (June 30, 2009) intros and links many stories of the amazing ways microbes manage without brains and can even appear to think ( well, not really, but ... ). Here's my favourite, but go here for more:
Many single-celled organisms can work out how many other bacteria of their own species, are in their vicinity – an ability known as "quorum sensing".How about a culturally (so to speak) adapted version of "Suicide is Painless"?
Each individual bacterium releases a small amount of a chemical into the surrounding area – a chemical that it can detect through receptors on its outer wall. If there are lots of other bacteria around, all releasing the same chemical, levels can reach a critical point and trigger a change in behaviour.
Pathogenic (disease-causing) bacteria often use quorum sensing to decide when to launch an attack on their host. Once they have amassed in sufficient numbers to overwhelm the immune system, they collectively launch an assault on the body. Jamming their signals might provide us with a way to fight back.