A drumlin differs from a roche moutonnee because a drumlin is

A drumlin differs from a roche moutonnee, in that it is a depositional smooth val shaped small hill up to 1.5 km long and 60 mm tall, having a steep end and a sloping end (elongated in the direction ice flowed). Roche Moutonee is an erosional landform formed when a glacier moving over the top of the rock moves one side giving it a jagged edge and abrading the other side giving it a smooth edge.