Today I experienced an unexpected all-morning pleasure. Two verdins — who are rare chickadees, desert-dwelling insectivores as tiny as hummingbirds and just as prone to plunging and darting, built a shelter right outside my library window to hatch their hoped-for offspring. It was most energetically and skillfully done, took six hours of continuous work by a monogamous pair of birds. Using errant twigs from the backyard, most of which were longer and perhaps heavier than themselves, they created a structure inside green foliage at the terminus of a hanging branch. I thought it an expert way of deceiving potential intruders; without foreknowledge of its existence, for sure you would pass right by the nest and notice nothing extraordinary.