Mongolian gerbil They are somewhat larger than mice, with a body about long (and a tail of similar length), with a body mass averaging in females and in males. The Mongolian gerbil is classified as a "prohibited new organism" under New Zealand's Hazardous Substances and New Organisms Act 1996, preventing it from being imported into the country. The species is also prohibited in the US state of California. "Meriones unguiculatus" evolved on the semideserts and steppes of Mongolia. There, they developed long legs for jumping and running from predators, teeth to deal with hard seeds and plant matter, and water conservation techniques
Guinean gerbil gerbil is a fairly large gerbil growing to a head-and-body length of about with a tail of about . The head has a slightly-rounded snout, large eyes and somewhat elongated ears. The upper parts of the body are greyish-brown, the individual hairs having dark grey bases, orange or brown shafts and black tips. The head and flanks are paler, the hairs lacking dark tips. The underparts, including the chin, throat, the inside of the limbs, the fore-feet and the upper side of the hind-feet are white. There is a clear division between the dorsal and ventral colouring. The tail is