Welcome to the hummingbird master class on nest concealment and feeding basics. These 2-inch-wide rufous hummingbird nests are built with moss, or other soft plant material, held together with spider web and camouflaged with lichen. And the lucky chicks, likely two, get a regurgitated feeding of nectar with a side of insects mom caught in midair. This amazing scene was captured recently at Billy Frank Jr. Nisqually National Wildlife Refuge in western Washington state. USFWS video: A. Froschauer

Hummingbirds are mesmerizing. They hover, dazzle, and shine. They fight, pollinate, and migrate. How and why do they do what they do? Take a fun, science-infused look at these tiny birds in a self-paced, online course from Bird Academy. Don't miss out—save 30% when you purchase before 6/24! | Cornell Lab of Ornithology