When walking, grolm appear almost awkward, moving with a waddling motion. All traces of awkwardness vanish when they run, as they can cover great leaps of ground in a hurry. Grolm communicate using a sharp, short barking call. With this call, they alert others of the species nearby that food has been located. Grolm travel in small packs of only a handful of individuals. When a victim has been located, they communicate over large distances using a short, gutteral barking call. With this call they alert other packs to join the chase. This behavior was first seen inThe Great Hunt when Rand al'Thor, Loial the Ogier and Hurin became accidentally trapped in a Mirror World.