This is the work of Modular Robotic's MOSS Robotic Building Toy. It's a series of little building blocks that, when assembled, function as little robots. They can drive, they can react, they can be built any way you like. Above is a cool hands-on video from Engadget and below is Gizmodo's in-depth explanation on how these work and where they came from.
This Toy Building Kit Lets You Make Tiny Driving Robots