Animals sleep in various ways depending on their species and habits. Some animals, like dogs and cats, may curl up in a ball or find a comfortable spot to rest. Other animals, such as horses, sleep standing up. Marine mammals like dolphins and whales practice unihemispheric slow-wave sleep, where one hemisphere of their brain sleeps while the other remains awake to help with swimming and breathing. Overall, animals have adapted different sleeping behaviors to suit their needs and environments.
