You might accidentally be killing hummingbirds

A hummingbird in Long Island, New York. | Bruce Bennett/Getty Images

Hummingbirds run on sugar.

The fuel powers their tiny, furious bodies and super-fast wings, which beat as many as 80 to 90 times per second. And luckily for them, they don’t seem to get diabetes, even though they have extremely high blood glucose levels.  

In the wild, hummingbirds, the smallest birds in the world, get their sugar from nectar-filled flowers, such as honeysuckle, lilies, and bee balm. But following...