Why cats like to crawl into boxes:
1. When a cat is in a new environment and feels scared, it will hide in a dark, small space to make it feel safe.
2. If the temperature is too low and the cat feels cold, it will also like to crawl into a box to keep warm. 
3. If a cat is in a bad mood, it may also hide in the box to regulate its emotions and relieve stress.
4. Cats are very curious and will crawl inside to see what's in the box.
5. When cats get bored, they will also crawl into boxes to pass the time and find fun.
