As a full-round action, a frost worm can emit a strange trilling sound that affects all creatures within a 100-foot radius. Creatures must succeed on a DC 18 Will save or be fascinated for as long as the worm continues to trill (the frost worm can maintain this trill by concentrating). Once a creature has resisted or broken the effect, it cannot be affected again by that same frost worm's trill for 24 hours. This is a sonic mind-affecting effect. The save DC is Charisma-based.