After all this fighting and eating and flying.

After all this fighting, feeding, and flying, hummingbirds sometimes need to sleep off the day’s events in a mild form of hibernation called torpor. Their hearts— proportionally the largest in the animal kingdom— slow from 1,200 beats per minute to a mere 50. But when they wake up 4 to 7 hours later, their lightning-fast metabolism kicks back into gear. With all this speed and strength, it’s no wonder the Aztecs revered these energetic birds as agents of the god of war Huitzilopotchli— a reminder that immense power can come in the smallest packages.