You may not have seen Common True Katydids before, but if you live in Alabama, it’s a sure bet you’ve heard them. They are responsible for one of the primary sounds of summer nights: the loud, percussive, chirp that sounds something like “kay-tee” or “kay-tee-did.”

Some folks characterize the sound as a loud, repeating “kay-tee-did, kay-tee-didn’t,” which has been a natural, long-running joke about indecisive young ladies named Katy.