Rhinos' horns are highly coveted by poachers. These latter are on the lookout for animals with the longest horns. Thus, rhinos with smaller horns are much less threatened, live longer, and reproduce more than their congeners. They are therefore in numerical superiority. This poses a problem for the species because short-horned rhinos have less chance of survival against their predators. The rhinoceros horn serves as a weapon against predators. As a reminder, four of the five species of rhinoceros in the world are on the verge of extinction.