Here is another kit that can teach your kids a thing or two about robotics and programming. The SunFounder Bionic Robot Lizard Kit comes with everything you need to build a 4-legged bionic lizard with programmable gestures and movement. It has 3 servos to imitate a lizard.
You can program the robot via Mixly or Arduino. You get a SunFounder Nano board, 9g SF0180 servos, battery, and everything you need to get started.