▁highly ▁developed ▁in ▁the ▁blind ▁mole - r ats , ▁whose ▁eyes ▁are ▁completely ▁covered ▁by ▁skin , ▁and ▁entirely ▁lack ▁external ▁ears ▁or ▁t ails . ▁ ▁All ▁of ▁the ▁sp al ac id ▁species ▁dig ▁extensive ▁bur rows , ▁which ▁may ▁include ▁storage ▁ch amb ers ▁for ▁food , ▁lat r ine ▁ch amb ers , ▁and ▁bre eding ▁n ests . ▁They ▁are ▁generally ▁solit ary ▁animals , ▁and ▁do ▁not ▁share ▁their ▁tunnel ▁complex es ▁with ▁other ▁individuals . ▁All ▁the ▁species ▁ ▁are ▁her b iv ores , ▁feed ing ▁on ▁roots , ▁bul bs , ▁and ▁tub ers . ▁ ▁They ▁give ▁birth ▁to ▁lit ters ▁of ▁up ▁to ▁six ▁young ▁after ▁a ▁gest ation ▁period ▁ ▁between ▁three ▁and ▁seven ▁weeks , ▁depending ▁on ▁the ▁species . ▁As ▁with ▁many ▁other ▁mu roid s , ▁the ▁young ▁are ▁born ▁blind , ▁hair less , ▁and ▁hel pl ess . ▁They ▁may ▁stay ▁with ▁the ▁mother ▁for ▁several ▁months ▁before ▁setting ▁off ▁to ▁establish ▁their ▁own ▁bur rows , ▁although ▁some ▁species ▁dis per se ▁as ▁soon ▁as ▁they ▁are ▁we an ed . ▁ ▁Character istics ▁Nor ris ▁et ▁al . ▁listed ▁several ▁characteristics ▁present ▁in ▁all ▁members ▁of ▁this ▁family ▁which ▁distinguish ▁them ▁from ▁the ▁rest ▁of ▁the ▁mu roid s , ▁( the ▁cla de ▁E um u roid a ). ▁These ▁are ▁" the ▁reduction ▁or ▁absence ▁of ▁external ▁eyes , ▁reduced ▁pin na e , ▁stock y ▁body , ▁short ▁tail ▁(