Rhinos are characterized by their large size (weighing up to one tonne or more), their horn and their thick protective skin. Rhinos are poached for their horns which are some cultures use for ornamental or traditional medicinal purposes. The horns are made of keratin, the same type of protein that makes up hair and fingernails.
They generally eat leafy material but because of their ability to ferment food in their hind-gut they can subsist on more fibrous plant matter if necessary. The two African species of rhino lack teeth at the front of their mouths so they rely on their powerful premolar and molar teeth to grind up plant food.