In the realm of biological entities with a closeness score of 9, hairballs stand out as enigmatic phenomena. Formed by the ingestion and accumulation of hair in the digestive tract, they are composed primarily of keratin, the protein found in hair, skin, and nails. Hairballs can vary in size from small pellets to large, dense masses, and are often found in animals that groom themselves extensively, such as cats and rabbits. Their presence can cause discomfort and health issues, and is often addressed through medical intervention, dietary changes, or grooming assistance.
