Why Care about Small Animals Moving Randomly -- Trap Function and Overview of the Trapping Process -- Random Displacement in the Absence of Cues -- The Geometry of Trap Interceptions -- Interpreting Catch in the Single Trap -- Competing Traps -- Proposed Experimental Method for Measuring C.S.D. of Random Walkers Via a Trapping-Grid -- Trapping to Achieve Pest Control Directly -- Automated Systems for Recording, Reporting, and Analyzing Trapping Data.