Colony Variation, Workers and Soldiers, and Measures of Spreading

Today I Learned:
1) There is good evidence that within-colony genetic variation is good for most social insects. There's some tension to this fact, because sociality requires very *close* genetic relatedness. There's a very narrow evolutionary window of intracolony relatedness through which a species has to pass to become eusocial.

2) I've always thought of ants belonging to one the four castes of queen, drone, worker, or soldier. Myrmicologists more or less also recognize this, but the worker is known as a "minor worker" and the soldier a "major soldier", and major soldiers also include storage castes in some species (as in, they store food for other ants).

3) The usual measure of "spreading" in statistical mechanics is mean squared displacement, which has units of distance^2. However! Many authors also measure in *root* mean squared displacement, which has units of distance. If you're ever reading about characteristics of diffusion, make sure you know which measure the author is using!