Visible in this photo: 8 hermits, 2 mud snails, 1 bubble shell snail, 1 leafy hornmouth snail, umpteen barnacles. Not visible but certainly there: at least 1 scale worm, several amphipods, a flock of copepods, and a crab (hiding under the double clamshell. And the 9th hermit, in a pinhead shell, somewhere among the barnacles.
Any time I look, the barnacle piles are crowded, mostly with hermits. Unless I've brought them some new fuzzy eelgrass; then they abandon the barnacles and go to work high overhead, cleaning eelgrass.