Although mostly adorable and sweet, capybaras can be a challenging pet. They do better in groups as they are extremely social animals, so pet owners should avoid getting a single capybara. This semi-aquatic rodent is legal to own in Texas and Pennsylvania. In some states they are legal but require licenses.The Capybara is a large, semi-aquatic rodent that is found inhabiting the water-logged regions of Central and South America. Closely related to other South American rodents such as Chinchillas and Guinea Pigs, the Capybara is the largest rodent in the world weighing up to 75kg and measuring nearly 1.4 meters long.