Did you know that sleep (or at least patterns of reduced activity that resemble sleep) have been found in almost all animal species and even some microbes?
Different species vary widely in how much sleep they need, when they sleep, and what stages of sleep they enter. Birds that migrate long distances seasonally are able to get by on microsleeps of a few seconds since they do not stop for long rests.
Humans definitely need much more sleep per night than “three,” whatever the hell that means. Additionally, evidence from history pre-industrialization and from studies of contemporary nonindustrialized cultures indicate that humans may be naturally inclined toward biphasic sleep, meaning they sleep twice in a 24-hour cycle - one nap typically in the afternoon, and then another bout of sleep at night.