Gerbils are illegal to own as pets in California and Hawaii because these states have a climate similar to the rodents' natural desert habitat. If they escaped into the wild, they could form colonies and disrupt endemic flora and fauna.

A litter of 15 was recorded in the 1960's by George Meares, a geneticist owner of a gerbil-breeding farm in St. Petersburgh, Florida, using a special food formula.

The great gerbil (Rhombomys opimus), the largest gerbil species, can reach lengths of up to 16 inches (40 cm). It is found in the deserts of Turkmenistan, Kazakhstan, Mongolia, China, Pakistan, Afghanistan, and Iran.

Gerbils live in dry and arid habitats. As a result, they have evolved a special kidney that retains as much bodily fluid as possible--meaning they don't urinate nearly as much as other rodents.

Sahara, a Mongolian gerbil (Meriones unguiculatus) born in May 1973 and belonging to Aaron Milstone of Michigan, USA, died on October 4, 1981, at the age of 8 years and 4 months.