Roborovski

Roborovskis (Phodopus roborovskii; formerly, Cricetulus bedfordiae) or desert hamsters (also known simply as Robos or Robs) are the smallest of all hamsters, averaging under an inch (2 cm) at birth, and (rarely) three inches (7.5 cm) during adulthood. Distinguishing characteristics of the Roborovskis are eyebrow-like white spots and the lack of any dorsal stripe (found on the other members of the Phodopus genus). The average lifespan for the Roborovski hamster is three years, though this is dependent on living conditions (extremes being four years in captivity and two in the wild).

http://en.wikipedia.org/wiki/Roborovski_hamster