Kids - young and younger - remember verdins because of their mustard-colored heads.
Another photo by Ned Harris
Verdins like nectar and will often get at it by pecking the bottom of a flower. They get the treat without doing the work of pollinating. I have some persistant verdins trying in vain to get into my hummingbird feeder. They can't hover like hummingbirds, but they have no trouble hanging upside down by one foot.