Words changing colour like crabs

From the Eumaeus episode of Ulysses by James Joyce:

Over his untasteable apology for a cup of coffee, listening to this synopsis of things in general, Stephen stared at nothing in particular. He could hear, of course, all kinds of words changing colour like those crabs about Ringsend in the morning, burrowing quickly into all colours of different sorts of the same sand where they had a home somewhere beneath or seemed to.

After the noncommittal vagueness of “things in general” and “nothing in particular”, I love how the image of local crabs, so suddenly specific, transports us (and Stephen) briefly out of the human domain across to the Dublin coast and the wordless creatures alive in the sand. It’s a strange and surprising analogy and one with a hint of synaesthesia.