Cats also have different levels of sleep, ranging from light to deep sleep. Their sleep cycle alternates between light and deep sleep, with most of their time spent in light sleep, in a state of "wanting to sleep." They only enter deep sleep when they are completely relaxed, which lasts about 5 hours a day. During deep sleep, cats' sleeping postures become quite unusual, and if they're having a sweet dream, it becomes even more unsightly.
