The Mongolian gerbil or Mongolian jird is a small rodent belonging to the subfamily Gerbillinae. Body size is typically 110–135mm, with a 95–120mm tail, and body weight 60–130g, with adult males larger than females. The animal is used in science and kept as a small house pet. Their use in science dates back to the latter half of the 19th century, but they only started to be kept as pets in the English-speaking world after 1954, when they were brought to the United States. However, their use in scientific research has fallen out of favor.
