Within the emerging sociology of sleep, researchers have, for strategic reasons, been mainly concerned with the sleep of human beings. But of what benefit is it to understand sleep as a trait of non-human entities? The aim of this article is to establish why it is worthwhile to expand how sleep is theoretically construed in sociological circles, so that sleep is more than just a property that human beings possess. In particular, I explore why it is fruitful to consider the sleep of non-human animals from a sociological perspective. I also examine the value of understanding sleep as a property ascribed to some technological devices. I then use the remaining part of this article to reflect on what it means to study sleep in these expanded ways. I relate non-human sleep to the emergence of the new materialism and explore how the concept opens up new areas for sociological inquiry.