If you’ve ever watched a hummingbird fly, you’ve probably seen how fast it beats its wings—up to 80 beats per second. That takes a lot of energy. But hummingbirds know that a good night’s rest is just what they need to build up and save that energy. At night, they fall into a deep sleep (called “torpor”), lowering their body temperature to save energy for the next day and dropping their heart rate from about 1,000 beats per minute to as low as 50 beats.

Scientists have discovered that hummingbirds that sleep longer wake up with more energy. In the morning, the energized hummingbirds are ready to buzz around and enjoy a breakfast of nectar.