The Bushtit, Psaltriparus minimus, is one of my nemesis birds. I’ve been walking trails on the coast and have people in front of me and behind say, "There goes one." But, I’ll be looking the wrong way every time.
It lives on the west coast of North America, mostly in moist forest and scrub understory. It is a small songbird and the only one in the Aegithalidae in the Western Hemisphere.
Classification:
Order: Passeriformes
Family: Aegithalidae
Genus: Psaltriparus
Species: P. minimus
Photos:
Girls on a wire

"A couple of female Bushtits waiting their turn at the suet feeder."
Photo courtesy of mgsbird
Bushtit

"The most carefully-pronounced name in American birding!
Tiny (<6 in.) unusual bird with lots of cool facts (courtesy Cornell’s All About Birds website): * The Bushtit often has helpers at the nest, birds other than the parental pair that feed nestlings. * All family members sleep together in the complex nest during breeding, but they leave it after the young fledge, and sleep on branches. * Males have dark eyes; females’ eyes turn yellow about a month after hatching."
Photo courtesy of Geoff Coe