[rmunn]

First thing that comes to mind is beehives and anthills. Highly ordered societies where each insect has a role to perform. Don't know how well you think that fits the "cathedral" model, but I'd say it's pretty close.

Beavers reshaping the landscape also comes close, but that's individual beavers acting more or less on their own, not a rigidly structured society like ants and bees, so perhaps the beavers are closer to the bazaar analogy than the cathedral.