Hexbug has been delivering insect-inspired robots for a while now. Based on simple electronics and basic bio-mechanics, they are robots-from-the-ground-up, similar to many of the BEAM robots in principle. In addition to their original Micro-Robotic Creatures, they have introduced an Inchworm, Spider, Crab, Ant, and nondescript Nano, as well as various terrains and habitats for these little creatures.
The HEXBUG Larva is the latest addition to the line. Though quite small, the robot has infrared sensors that allow it to detect obstacles in its wriggly path. The robot is then capable of steering clear of those obstacles. All of this is pretty good for a robot this size, but not earth-shattering. The thing that sets the Larva apart is the bio-mimetic motion. It's both fascinating and -- if you are not into creepy-crawly things -- perhaps a bit unnerving. Personally, I think it is fantastic!
Here's where you can get the Hexbug Larva in a variety of colors.