Ear mites themselves will not cause death in cats. However, it will cause severe itching of the ears, and the cat will scratch its ears frequently or shake its head. In severe cases, it can lead to otitis media, hearing loss, ear hematoma, etc. Moreover, ear mites are highly contagious in cats, so it is recommended to pet them. Once you find that your cat has ear mites, you need to treat them promptly.