Believe it or not, there's an article on slime molds that I'm going to recommend as utterly fascinating.
Well, it's by Carl Zimmer, so maybe that makes it less of a surprise. Anyway, here's a taste:
Slime molds first came to scientific fame in the mid-20th century with the work of the Princeton biologist John Tyler Bonner. Dr. Bonner learned of a North American species of slug-forming slime mold called Dictyostelium discoides and began to raise them in his lab, studying them as a simple analog of animal embryos.
Today, biologists no longer think of Dictyostelium as an embryo: It is more like a society of amoebas that come together for a common cause, for which some will sacrifice themselves.
The organisms respond to starvation by rushing together by the thousands into a single blob. The blob stretches out into a slug-shaped mass about one millimeter long (one twenty-fifth of an inch), which then crawls like a worm toward light.
Once it reaches the surface of the soil, the slug undergoes another transformation: Most of the cells turn into a stiff stalk, while the others crawl to the top and form a sticky ball of spores. They stick to the foot of an animal and travel to a hospitable place.
Inside the slug, about 1 percent of the amoebas turn into police. They crawl through the slug in search of infectious bacteria. When the amoebas find a pathogen, they devour it. These sentinels then drop away from the slug, taking the pathogen with it. They then die of the infection, while the slug remains healthy.
When the slug is ready to make a stalk, more amoebas must die so that others can live. They climb on top of one another and transform their insides into bundles of cellulose. Eighty percent of Dictyostelium cells die this way, allowing the survivors to climb up their lifeless bodies and become spores.
It also appears that slime molds are capable of recognizing their relatives, are good at making maps, and also act like humans when they're looking for food. Ooze on over to the rest.