The spiny rats are a group of hystricognath rodents in the family Echimyidae. They are distributed from Central America through much of South America. They were also found in the West Indies until the 1800s. Some authorities consider the nutria from southern and central South America to be a part of this family.
Most spiny rats resemble spined rats. They are more closely related to guinea pigs and chinchillas. Most species have stiff pointed hairs that allow for protection.
Many echimyids can break off their tails when attacked. This action confuses predators long enough for the animal to escape. Unlike lizards, however, the tail of spiny rats does not regenerate. This technique can obviously be used only once in each individual’s lifetime.
Most spiny rats are rare and poorly known, but a few are extremely abundant. They are restricted to regions with an abundant source of water. They are almost exclusively herbivorous.