There are many reasons why cats twitch while sleeping. Generally, they are divided into the following reasons:

1. Cats may have the habit of dreaming just like us humans. Once they chase or fight in their dreams, it may cause the cat's legs to twitch, which is generally a subconscious action.

2. Cats’ sleeping habits and surrounding environment may also affect their sleep quality, leading to convulsions.

3. Cat convulsions may also be caused by their own health problems, such as epilepsy, hypocalcemia, heart disease, muscle disease, etc.

4. If a cat twitches, you should also consider whether it is caused by internal parasites. If this situation is serious, it will affect the cat's health.