The kinglets are here!

Every year at this time, tiny Golden-crown kinglets sweep through the yard. They're very tiny birds, impossibly cute. Usually they're in groups high up in the fir trees, but this morning I saw three hopping around like ping-pong balls in the driveway and calling to each other in their high-pitched voices. One came within a few feet of me, probably not even noticing what I was. Here's a photo from Birdnote.org.

It shows how pretty they are but doesn't give the right impression of how round their bodies are.
Here's another, source unknown.

To help identify them in your yard, you can listen to their sounds here.