A Smart Small Trader, a rare Bird.

Why do some birds hang out on the backs of rhinos?
The birds – called Oxpeckers – are there for the food. Oxpeckers pick blood-sucking ticks and other parasites off the rhinos.
The relationship between the oxpecker and the rhinoceros is an example of "mutualism", a relationship in which both organisms benefit. In other words, it's a win/win situation – the rhinos get rid of unwanted pests and the birds get a tasty meal.