pygmy sand cricket, any member of the orthopteran family Tridactylidae of about 60 species that often inhabits moist sandy surfaces near a lake or stream. Tridactylidae have forelegs, modified for digging, that resemble those of a mole. Adult pygmy sand crickets are up to 10 mm (about 0.4 inch) long and are active jumpers. The males do not sing.