Whether or not all rhinos bear a grudge is up for debate, but most observers seem to agree that a large part of why rhinos charge even inanimate objects is because of their poor vision. The beasts are most certainly nearsighted and can't see very well beyond 90 feet (27 meters) [source: Maydon]. They do, however, have a powerful sense of smell and hearing, so if they detect an unfamiliar scent or hear an odd noise, their tendency is to charge in the general direction of it.
Not all rhinos charge as frequently as others. Black rhinos, which are common in Eastern and Southern Africa, are the most likely of the five rhino species to tackle without provocation. The white rhinoceros tends to be more docile and the Javan and Sumatran species supposedly lack the presumed bad temper altogether.
Although the tamer species have been reported to charge on occasion, those instances may simply be a case of improper navigation. Due to their poor vision, these peace-loving rhinos may actually be trying to escape the supposed threat but, instead, end up running toward it [source: Bruton].
In other instances, the rhinos may not be trying to scare something off or to escape, but simply burning off steam. When they become aggravated or hurt, the animals sometimes take out their frustration on inanimate objects like trees or termite mounds, repeatedly smashing them with their horns until the object disintegrates [source: Skinner].
Whether a rhino is likely to charge also depends a bit on its personal history and individual temperament. If it was raised in a relatively peaceful, non-threatening environment, it will probably be less aggressive. If, however, it has been frequently hunted or otherwise provoked, it will no doubt be easily perturbed. Either way, it's a sure bet that if you come between a female and her calf, you better start moving.
Whether a rhino's charge is coldly premeditated or initiated out of fear and confusion doesn't really matter once its lumbering body gets going. Not only can their horns reach frightening lengths, but the animals are surprisingly fast for their size, able to reach speeds of up to 40 mph (64 kph) [source: National Geographic, San Diego Zoo].
Of course, unless it's a tree or a termite mound, the target has the benefit of full vision capabilities. For more on rhinos, feel free to charge to the next page.