Slime molds [are fascinating](https://www.youtube.com/watch?v=dYQG6ac38UA). They can live as single-celled organisms or work together as a colony that differentiates functions and exhibits learning behaviors without having anything like a brain. Training one slime mold and then allowing it to fuse with another transmits the training with the new slime mold.
As John Tyler Bonner, a professor of ecology [put it](https://www.princeton.edu/news/2010/01/21/sultan-slime-biologist-continues-be-fascinated-organisms-after-nearly-70-years), slime molds are "no more than a bag of amoebae encased in a thin slime sheath, yet they manage to have various behaviors that are equal to those of animals who possess muscles and nerves with ganglia – that is, simple brains."
