MovingUpintheWorld

Somemigrationsmoveupanddown.Forexample,Dallsheepmoveupanddownmountains.Theymoveastheseasons change.

Inspringandsummer,theystayhighinthemountains.Thereisfoodthere.Theyeatgrass.Beforewintercomes,theymovedownthemountain.Theyneedmorefood.Thereisfoodfurtherdown.Howdotheyknowtheway?Scientiststhinktheoldestsheepteachestheyounger ones.