Zivko the Robot. Our best selling STEM kit ever! Just call her (or him--it’s unclear and we don’t like to ask) “Zivko” because “the Robot” is her last name. Using just a screwdriver and side cutters, you build Zivko from this 107-piece S.T.E.M. kit. Set the mode for “Follow Me” or “Explore,” and Zivko will, yes, track you, or evade obstacles, respectively, via an infrared sensor and micro-controller programming. Interactive LEDs and sounds abound. Measures approx 5" x 5-1/2" x 6-1/2" when assembled with all (6) legs. You add (4) “AA”s for power, which is the least you can do for someone this cute. Ages 10+.

It doesn't get much cooler in the robotic-arm-kit game. The assembled STEM educational arm is 15" tall x 9" long x approx 3-1/2" wide. It's 2-pronged hand opens to 1-3/4", lifts up to 3.5 oz (100g), swings 120 degrees at the wrist, pivots 300 degrees at the elbow, and sits on a base that swings 180 degrees up and down and rotates 270 degrees, like, well, an arm. Controlled by (5) 2-axis joy-sticks and powered by (4) D-Cell batteries that you provide. Includes a hand-mounted search light and over-torque and gear-breakage alarms, which is more than your arm has. Requires a diagonal cutter and Philips screwdriver for assembly of its 200+ pieces and is made for ages 12 and up.

Everything you need to build a little DC motor is included in this kit (except sandpaper, screwdriver, scissors and, of course, an AA battery). The instructions are simple and explain the theory as well as assembly. Fun and educational for ages 12 and up.

if you want to sound like a steam engine, and who among us doesn't? This Velleman® steam-engine sound generator kit comes with circuit board, components, battery connectors, speaker and instruction sheet. You add solder, a soldering iron and a 9V battery. Volume and (implied) speed are adjustable and there's a horn button, so it'll go both choo-choo and whoo-whoo. Great for train hobbyists or people bored with their doorbell. Ages 10+.

with our best selling electronics kit. Build 100 or more electronic projects from a Reflection Detector to a Simple Salt Water Alarm with Snap Circuits Jr. The Elenco kit, a Dr. Toy Winner, has a grid base and a selection of conductors, resistors, switches, integrated circuits and more, for a total of (30) color-coded snap-in parts. For ages 8 to 108, the easy-to-use components and well-designed instruction manual make this a perfect way to spend some quality time with a bright young child! AWARDS: The National Parenting Center-Seal of Approval, Dr. Toy 100 Best Children's Products, Dr Toy Best Educational Products. Ages 8+. See our full line of Elenco Snap Circuits here!

His name is Tobbie II, and although he stands only about 6-7/8” tall, he does sport (6) actual feet, which is why he has such an agile, 360-degree, free-rotation body. You build him yourself (easy-peasy if you’re over 10) and program him on your computer, tablet or smartphone. Comes out of the box pre-programmed with Assembly Checker and Program #1, so the fun starts right away. Use him as a light tracker or thermometer, or to play rock-paper-scissors or bowling, or as a notice board, calculator or compass, or as a pet who will follow you. He’ll do other things, too. Includes a 36-page manual, and all you add is a quartet of “AAA” batteries and some common hand tools.

The vegetable- or fruit-powered clock never gets old. You get (2) copper and (2) zinc electrodes, 4" x 1/8", a couple of pieces of wire and a little 1-1/8" dia LCD clock. You don't add any batteries, just bring a lemon, lime, grapefruit, potato, kiwi, strawberries (or some cola if you're not a healthy eater) and time is on your side. Ages 5+.

An advanced kit compared to the others, a little more deluxe and a little more complicated. It is an AM/FM radio kit from Elenco with over 80 pieces divided into lesson groups. PC board shows component placement to help learning and to minimize errors. It has (14) transistors and (4) diodes and the case measures 11"x 5"x2-1/4". Ages 12+, as considerable soldering is required.

Cool kit to introduce the beginner (age 10+) to the fabulous world of electronics. You will learn the basics of putting together circuits through over 50 projects building actual devices like an alarm, a radio, a metal detector and much more. The simple but complete instructions explain voltage, current resistance etc. This kit from Elenco is a giant "breadboard" with wires that can be connected to form the circuits as explained in the instructions…and all without soldering! A fabulous educational item at a fabulous surplus price!! For ages 10+.

Our robotic kingii dragon (Chlamydosaurus kingii, or frilled-neck lizard) is better than a puppy because you don't have clean up after it and it won't chew the furniture. This STEM education kit has (2) motors and digital control via IR sensors to activate LED eyes, motorized mouth and pop-out neck frill, plus "Escape" and "Chase" modes, which make it retreat and follow you using IR sensors, respectively. You'll need (4) "AAA" batteries and some patience, as this kit is delightfully challenging. Finished dragon will be 13-1/2" long x 8-1/4" x 5". For ages 10+.