I scream, you scream, we all scream. For ice cream, sure, but also for fear, excitement, sexual pleasure, pain, anger, and—if online commenters are to be believed—memes 😱. Screaming is exhibited by many animals, but no species uses this extreme vocalization in as many different contexts as humans. Though we're pretty good at recognizing a scream when we hear one, the wide variety of screams makes it difficult to pin down what defines them.