Bathrooms are often warmer than other rooms in the house, especially in the winter. This is because the hot water heater is typically located in the bathroom.
Bathrooms are often a quiet and private place, which can be appealing to cats. They may feel safe and secure in the bathroom.
Cats are attracted to water, and the bathroom is often the only place in the house where they can get to it.
Cats are fascinated by their own reflections, and the bathroom mirror is often a great place for them to see themselves.
Bathrooms often have strong scents, such as those from soap, shampoo, and lotion. Cats have a keen sense of smell, and they may be attracted to these scents.
Some cats feel more secure in the bathroom, especially if they are scared or stressed. The bathroom is often a small, which can provide them with a sense of safety.
If your cat's litter box is in the bathroom, this is another reason why they might like to hang out in this room.