INDIANAPOLIS (WISH) — One of the biggest mysteries of the universe is not what lies in the vast expanse of space or humanity’s true purpose. The biggest mystery is actually what lies in the mind of a cat.

Cat owners around the world understand that learning their cat’s personality can be challenging. Questioning whether or not a cat loves its human may be a struggle many pet owners face.

While other types of pets might be more vocal in showing their love, cats are far more subtle. Here are a few signs that your cat actually does love you, according to Dr. Katie Grzyb, a veterinarian and writer with PetMD.

Headbutting, or “scenting” you

Cats may bump their head against you or rub their cheeks on your skin to show affection. According to PetMD, this is both a social behavior developed in kittenhood and the cat’s way of claiming their human.

The “slow blink”

Eyes tell many stories. While eye contact with some animals should be avoided, it is the opposite with cats.

Cats use eye contact with people to show they love and respect them. Grzyb says cats will make eye contact with lowered eyelids and steady, slow blinks. It is the feline version of a kiss.

Invading personal space

Cats are protective of their space. A cat allowing a human into its space is a sign of trust and respect.

Cats sleeping with their humans, even if it’s for a brief moment, is also a sign of trust. This act shows the cat trusts its human to protect it, or will protect its human if needed.

“Talk to the tail”

The movement of a cat’s tail is a language of its own. A happy cat will greet its human with an upright tail, or a tail shaped like a question mark.

Grzyb adds that cats also slowly wag their tail and allow its tail to touch their human when sitting nearby. Cats might also rattle their tail while walking to show their happiness.

Showing their belly

A cat showing a human its belly is often seen as the ultimate sign of trust for a cat. Cats only show their bellies when they’re completely relaxed.

This is not an invitation to pet the cat’s belly, according to PetMD. It is instead another form of communication that the cat feels safe.

They include their human in bath time

Including their human in their grooming routine is seen as another ultimate sign of affection.

Grzyb also says that grooming builds a bond between cats and humans, allowing them to “mark” each other. Be cautious, though, if the cat starts growling or swishing their tail quickly. Grooming, especially with brushing, can be overstimulating.

Other ways cats show affection include kneading, purring, greeting their human at the door, and bringing presents — even if the present is a dead bird.

How does your cat show they love you?