The issue of whether young children use spatio-temporal information (e.g., movement of objects through time and space) and/or contact-mechanical information (e.g., interaction between objects) to search for a hidden object was investigated. To determine whether one cue can have priority over the other, a dynamic event that put these cues into conflict was created, with only spatio-temporal information being valid. The 3-year-olds used in the study were found to use the valid spatio-temporal cue exclusively and seemed to ignore the contact-mechanical cue. Both search behavior and eye tracking during the event support the view of a sophisticated sensitivity to the validity of a cue in indicating a target's hidden location. (Contains 2 figures.)