Trollocs are fearful creatures, with self-preservation generally being one of the only reasons they abstain from violence and killing. They also fear rivers and crossing bodies of water, as they cannot swim. To some extent they fear, and hate, wolves and kill them whenever possible; however while they may favor their chances against a lone wolf, Trollocs fear packs of wolves according to Perrin's friend Elyas Machera who is a wolfbrother. More than anything, they fear Shadar Logoth, or more accurately Mashadar, and also the Aiel Waste which they refer to as the Dying Grounds. It generally takes the insistent driving from a Myrddraal to get them to enter either area.