How Magical! The Line Tracking Mouse Kit is a smart Robot Mouse that tracks a black line using a photo interrupter for its eyes. How Funny! Create a twisting and turning road layout yourself with black tape on a white background. See how it tracks the black line to find the target.;From the Manufacturer;How Magical. A smart Robot Mouse tracks a black line using a photo interrupter for its eyes. How Funny. Create a twisting and turning road layout yourself with black tape on a white background. See how it tracks the black line to find the target. These robots are designed to introduce students into the exciting world of electronics. Designed with high schools and technical colleges in mind, these robots come complete with detailed instructions. This kit requires soldering and makes great class projects for beginners.