Updated: Nov 28, 2019
The main reason is that they’re confined, enclosed spaces. Cats are ambush predators and finding confined places where they can hide, hunt prey and feel safe and warm is an instinctive behavior. also The cardboard cat house provide a cozy, safe place to sleep, which is very important given that the felines sleep for up to 20 hours a day.
"Cats likes cave boxes because they are cryptic animals; they like to hide," Stephen Zawistowski, science adviser for the American Society for the Prevention of Cruelty to Animals, told Business Insider. "And a box gives them a place of safety and security."