Rhinos are critically endangered because poachers kill them for their horns, which are made of keratin and believed to have magical or medicinal properties. There are five types of rhinos with different characteristics like lip shape and horn number. Rhinos can weigh up to 3,600kg and have poor eyesight but strong senses of smell and hearing. They are herbivores that eat plants. Poachers kill rhinos for their horns to supply the illegal wildlife trade.