Cats sleeping in the litter box may be a sign of stress. Cats' preference to sleep in the litter box may be related to their timidity and lack of security. When cats have just arrived in a strange environment, or there are things or people that make them feel uneasy, they may choose a litter box with their own scent to rest in to gain more security.

However, please note that cats sleeping in the litter box is not always due to stress. Sometimes, cats may enter the litter box simply out of curiosity or to play. Therefore, when determining whether a cat’s behavior is caused by stress, it is necessary to consider the cat’s overall behavior and health.