A small mammal (family Ochotonidae), related to rabbits and hares, that has short ears, no visible tail, a round body, and hindlimbs with four digits only slightly longer than the forelimbs with five digits. Pikas inhabit mountainous regions throughout the northern hemisphere, at elevations higher than those other mammals can tolerate. They shelter in burrows and do not hibernate. There is one genus, Ochotona with 30 species.