Vampires are soulless creatures hence they do not sleep because they don’t need it. During the night they are active and busy hunting for fresh human blood for feasting, fulfilment, and excitement. When dawn breaks, vampires immediately go back to their lair and hide from the sunlight because it is one of their greatest enemies. We often see in movies the vampire running to its coffin when it senses dawn coming because it knows that exposing itself to the sun is instant death.
Besides, vampires don’t even need to sleep for energy restoration because they get their energy from the blood they drink. The amount of blood they consume determines their lifespan because it is what sustains them. The longer they live, the more they consume. However, this doesn’t mean that they are immortal because the stake through the heart, a bolt of lightning or electric current are still enough to kill them.
Although they don’t need to sleep, it is not a bad thing for them to enter a supernatural slumber. They do so to delay the day’s end and it also helps them pass the time. In addition, they can rest assured that their bodies are safe and well-protected from any threat that might come looking for them. This is why they hide in cemeteries during the day, to prevent any accidental exposures to the sun. However, they are able to do this because their eyes can see in total darkness.