Every spring the barn swallows return to the marine lab, not exactly on the first day of spring as in San Juan Capistrano, but I always know it's really spring when they arrive. They build their mud nests against the eaves of the buildings, and spend time chattering at us from the fences.
However, the swallows don't always choose the best location for their nests. About two weeks ago a pair of swallows were determined to build their nest here:

The poor birds would build up a small pile of mud, only to get all twitterpated and bent out of shape whenever anybody walked out the door, which is every few minutes. I'm not sure if the proto-nests fell down by themselves or were hosed off, but it took the birds about a week to take the hint.
Then they decided to build the nest here, which makes a lot more sense:

Doesn't the little guy (or gal) look pretty satisfied up there? This site is farther away from any doors and is on a building that people don't go into or out of nearly as frequently, so the swallows should be able to raise and fledge their young successfully.