In the African savannahs, it is common to see herbivorous mammals accompanied by oxpeckers that feed on ticks and larvae of insects lodged in their skin. They also eat insects raised by their footsteps. Large mammals find in them a way to clean inaccessible places (back, muzzle, ears…) and let them do so although their action slows the healing of wounds. Such an association between two species that coexist in mutual interest is a form of symbiosis called mutualism.