You’ve probably come across the phrase “blind as a bat” at some point in your life. But, as it turns out, bats aren’t blind.

To figure out where this myth started and why it’s so popular, The Verge called up Winifred Frick, the senior director of conservation science at Bat Conservation International. Not only are bats not blind, most species aren’t the disease-carrying, bloodsuckers we often see on television. In fact, bats play vital roles in ecosystems around the world.

An infection called white-nose syndrome is wiping them out at alarming rates, however. It’s hard to tell how that might affect their ecosystems in the future. Check out the video above to learn more about bats, because someone definitely lied to you about these charismatic little mammals.