Cats communicate with each other through a variety of vocalizations, body language, and scent marking. They use meows, purrs, hisses, and growls to convey their feelings and needs to other cats. They also use their body language, such as tail position, ear placement, and facial expressions, to signal their intentions and emotions. Additionally, cats use scent marking through rubbing objects with their scent glands to establish territory boundaries and communicate with other cats.