Mousekids is an easily adaptable tool for examining decision making behavior in children and adults. It was designed analogue to the classic “mouselab” paradigm (Payne, Bettman & Johnson, 1988). In contrast to mouselab tools typically used with adults, the Mousekids program contains two different phases: In the learning phase, participants learn the validity of each cue, one after the other; in the subsequent testing phase, participants then make a series of decisions. The cue validities are symbolized throughout the entire game using so-called “smart circles”. Due to the experience-based learning of the cue validities as well as their simple depiction based on absolute frequencies, the Mousekids tool can be used to examine probabilistic inference-based decisions in children even as early as preschool.