1. When a cat is eating or grooming itself, it is suddenly interrupted by something else, causing its attention to be diverted, so it forgets to retract its tongue.
2. Cats with small chins and long tongues are more likely to stick their tongues out when their muscles are relaxed. So these cats often stick out their tongues when they are daydreaming or sleeping, which is normal. 
3. When the weather is particularly hot, cats will occasionally stick out their tongues to cool down, just like dogs. Some cats will also do this after strenuous exercise.
4. If your cat frequently sticks out its tongue, drools, or has a decreased appetite, it may be due to oral diseases such as stomatitis or periodontitis, and you should take it to the vet for examination as soon as possible.
