Bushtit

Bushtit. ©Teresa Shumaker

Of all the birds I have seen, this bird has to be the cutest. It is super tiny, a little bigger than a hummingbird. It travels in flocks that will descend on a tree right in front of you, not caring whether you are close, and they forage by placing their body in some of the most comical ways.
My personal favorite is when they hang upside down, decide there isn't anything they want, so they just let go of the limb and burst into flight as they somersault in midair.