Get ready for some seriously spooky fun — with a surprise spider that senses motion! Rig up an electric circuit with a motor and a motion-detecting sensor, and watch as your creepy critter contraption drops on unsuspecting victims, er, friends. Explore the spooky science behind your sensor, then discover other marvelous machines that detect motion — just like your spider. This is one Halloween trick that’s a treat to build!

Check out the video tutorial and build along with us!

• Craft a spider out of yarn, a chenille stem, and up to 12 wiggle eyes!

• Get hands-on with engineering. Build the motor box using the included sensor (which sends a signal when it detects movement), transistor (which switches the motor on when it gets a signal), motor (which spins to drop your spider), and battery pack (which powers your spider’s movement).

• Includes spiderweb roving to customize your contraption and a mounting strip to hang it from your wall.

• Get creative! You can swap out your spider for any creepy-cute critter you make from at-home materials.

• 29-page booklet includes step-by-step troubleshooting instructions, a rundown of how your sensor works, and fun facts about motion-sensing alarm clocks, buses, and other marvelous machines.

• Spider box dimensions: 6.25 x 4.25 x 4.25 inches (15.9 x 5.7 x 5.7 cm).