pika, short-haired mammal related to rabbits and hares, also called mouse hare and rock rabbit. Pikas live above the timber line in the mountains of N Asia and W North America. The pika differs from the rabbit in that its body is smaller and the ears on its blunt head are shorter; also unlike the rabbit, the fore and hind limbs are about equal in length. The pika moves with a scampering gait. Its fur varies from red to gray and covers the soles of its feet. Pikas generally shelter in communities beneath rocks, although some Asian species burrow. Their diet consists primarily of green plants. Because food is difficult to obtain in winter in the harsh tundra environment, pikas cut, sun-dry, and store vegetation for winter use. Pikas are classified in the phylum Chordata, subphylum Vertebrata, class Mammalia, order Lagomorpha, family Ochotonidae.

Any of numerous round-eared, tailless members (genus Ochotona, family Ochotonidae) of the rabbit order (Lagomorpha), found in Asia, eastern Europe, and parts of western North America. Though not hares, they are sometimes called mouse hares. The hind legs are less developed than a rabbit's; pikas scamper rather than bound. Their brownish or reddish fur is soft, long, and thick. Most pikas weigh between 4.5 and 7.1 oz. (125 and 200 g) and are about 6 in. (15 cm) long. Many species live in rocky, mountainous areas, but some Asian species inhabit burrows. Pikas do not hibernate, but in summer and autumn they “harvest” vegetation and store it in protected places (e.g., under rocks) to be eaten in winter.

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