In this exercise, students investigate how desert scorpions locate their prey using a method similar to how seismologists locate earthquakes. The scorpion has specialized sensors in its feet to detect P and Rayleigh waves transmitted through sand. First, students draw waves spreading out from a walking spider like ripples in a pond. In this forward problem, students calculate the wave travel times through sand, create travel-time curves, and calculate the slopes of the lines. Next, in the inverse problem, students are given the Rayleigh minus P times and must use their travel-time curves to determine the distance from the spider to the scorpion. Finally, students draw circles on a map of the scorpion's legs, thereby using triangulation to determine the spider's location. Has minimal/no quantitative component Uses geophysics to solve problems in other fields