Have you ever wondered how we identify the ferals and community cats that have been "fixed"? The answer is shown in the image to the below. This is known as "ear tipping" and there are no adverse effects to the animal. A small piece of the ear is removed (usually during the spay/neuter procedure) while the animal is under anesthesia. This is a universal sign to both animal welfare advocates and to animal control officers that this feline has already been sterilized.