A tiny 4 minutes of sleep was recorded by one specimen, out of the small fraction of female fruit flies that slept for an average of 72 minutes daily.
These birds slept for an average of 42 minutes in air, using only half of their brains.
They do occasionally take naps, but never fall asleep soundly and without awareness.
The first month of a newborn bottlenose dolphin's life is spent without sleep. This is due to the fact that they must surface for air every three to thirty seconds.
It was believed that creatures without a central nervous system, like jellyfish, were either incapable of sleeping or did not require it. Jellyfish have been demonstrated to experience a "sleep-like" state at night, nevertheless.
Orcas, also referred to as killer whales, are another species whose young go without sleep for the first few months of their lives. You can witness juvenile orcas swimming around even when the adults are napping.
Most insects, including butterflies, enter a state of torpor rather than true sleep. While they are in a state of trance, their body temperature drops and their heart rate slows down.
Walruses are sometimes thought of as being sleepy and drained, but these big animals can easily remain awake for 84 hours at a stretch. These are the hours they'll largely be swimming and hunting for food.