Animal Tail Size Lifespan Sociability Sleep Schedule Diet Hamster Short and stumpy Depends on the species but often around 4 inches 1.5 to 3 years Not very social with humans or hamsters; like to live alone Mostly nocturnal Omnivore Gerbil Long and covered in fur, like a mouse's 4 to 7 inches 3 to 4 years Very social; like to live with other gerbils and be handled by humans Mostly diurnal Omnivore Guinea pig No tail 8 to 10 inches 5 to 7 years Very social; like to live with other guinea pigs and be handled by humans Mostly diurnal Herbivore Golden hamsters, or Syrian hamsters, are usually around 6 to 8 inches long, while most Chinese hamsters are in the 3-to-5-inch range; and dwarf hamster species usually cap out around 4 inches long.