A paca is a member of the genus Cuniculus of ground-dwelling, herbivorous rodents in South and Central America. It is the only genus in the family Cuniculidae. Pacas are large rodents with dots and stripes on their sides, short ears, and barely visible tails. They are also known in Belize as "gibnut" or, having been served to Queen Elizabeth II, as "the royal rat". In the Amazon basin they are known as "majás".
The Smithsonian Tropical Research Institute in Panama has studied the possibilities of developing the paca as a viable high-priced food supply for the tropics.
The lowland paca is found from southern Mexico to northern Argentina. They primarily live in rainforests near streams, but can also be found in a wide variety of habitats, including mangrove swamps, gallery forests near water currents, and even in public parks. They have been observed up to 2,500 m (8,200 ft) above sea level.
The smaller mountain paca lives in the northern Andes and the Páramo grasslands, with a peak occurrence between 2,000 and 3,000 m (6,600 and 9,800 ft) above sea level.