Using a bunch of 3d printed parts, I made a robot to chase squirrels. First, the nerf barrel (with a squirrel on top) rotates every 30 seconds from left, to center, then to right. If the robot detects a squirrel, stage one is initiated. The robot charges forward then retreats. If the squirrel is still detected, the robot fires a nerf dart toward the offending creature. If the pest persists, the robot blows up a balloon and (using a heated resistor) pops the balloon. http://youtu.be/tNoa7V9rEC4Instructions can be found at: http://www.instructables.com/id/Squirrel-Chasing-Robot/