Spalax Nannospalax The blind mole-rats, also known as the fossorial or subterranean mole rats, are a subfamily (Spalacinae) of rodents in the family Spalacidae, found in eastern Europe and western and central Asia.

Some authorities treat all species as belonging to a single genus, Spalax, but more recent studies indicate a deep divergence between both lineages dating back to the Late Miocene, supporting them as being distinct genera.

Unlike many other fossorial rodents, blind mole-rats do not have enlarged front claws and do not appear to use their forearms as a primary digging tool.

Blind mole-rats may have evolved from spalacids that used their front limbs to dig, because their olecranon processes are large relative to the rest of their arms.

A few publications, such as Avivi et al., 2002, have proven that the circadian genes that control the biological clock are expressed in a similar manner as in sighted, above-ground mammals.