Guinea pigs are small, domesticated rodents that belong to the family Caviidae. They are native to the Andes mountains in South America and are popular pets due to their friendly nature. Typically, they weigh between 1.5 to 2.5 pounds and have a lifespan of about 4 to 6 years. These animals are social creatures and thrive in pairs or groups. Guinea pigs require a balanced diet that includes hay, fresh vegetables, and specially formulated pellets. They are known for their vocalizations, which include squeaks and purrs, expressing their emotions and needs.