If you have a cat, chances are you’ve woken up with its nose just inches from your face—or even curled up on top of your head or chest.

This behavior, which can seem either sweet or intrusive depending on how you see it, has several explanations that mix instinct, attachment, and a need for security. Both feline behavior science and the experience of cat owners agree that it’s not random at all, but rather a pattern that reveals a lot about the relationship between the cat and its human.

One of the most common reasons is the search for warmth.

The head and face radiate more heat than other parts of the body because of the concentration of blood vessels. For a cat—who prefers temperatures slightly warmer than what humans usually find comfortable—this source of heat is irresistible, especially at night when the air cools down.

Another key reason is the sense of safety.

Cats, while natural predators, are also potential prey in the wild. Sleeping near their owner’s face gives them the feeling of being protected by the one they trust most. In their minds, snuggling close to your face while you sleep is the equivalent of finding the safest spot in their “territory” to rest without worry.

Emotional bonding also plays an important role.

Cats form social connections through physical contact. Approaching your face, brushing you with their nose, or rubbing their head against you is a way of depositing pheromones that mark you as part of their group. This marking behavior is instinctive, and by doing it while you’re asleep, the cat reinforces its sense of belonging.