The leaf-cutting ants, found in Central and South America as well as in the southern United States, have a mutually beneficial, or symbiotic, relationship with certain fungi of the genus Septobasidium. Because the ants are not able to digest the cellulose found in leaves, the fungus breaks down the cellulose—a food source for the fungus—and converts it into carbohydrates and proteins, which is perfect for the ants to digest. The ants then eat the fungus. Thus, the ants provide the fungus with a guaranteed food supply and eliminate competing fungi. Interestingly enough, the ants and fungus are not known to occur independently from each other.