A cat's body shivering when lying down may be caused by timidity, fear, feeling cold, intestinal disease, intestinal blockage, etc. You need to observe whether the cat has other abnormalities. If the cat has no abnormalities, don't worry. Just pay attention to keeping the cat warm; if the cat often suffers from this condition, or suffers from poor spirits, vomiting and diarrhea, etc., it is best to send it to a pet hospital for examination.