Pikas are small hamster-like animals, with short limbs, rounded ears, and short tails.Pikas are vegetarians, feeding on the stems and leaves of various grasses, weeds, and small shrubs. They are remarkable for their highly-developed haymaking behavior. By early July, pikas begin periodically clipping or pulling up stems and twigs, which they carry back to the colony in their mouths and store under overhanging rocks, in crevices, and along the edges of boulders. Young pikas grow surprisingly quickly, reaching their adult size after only 40 to 50 days. The average maximum natural life span for a pika is three years.