GoForSmoke:
They might use 6 micro motors of some kind. A surfeit of tech toy parts means not having to improvise so much.
Well, it's not about availability. Few things are as reliable as a bean counter's input. If it can be made with less for cheaper, you can bet that's the route chosen.
2 motors, independent sides, and on each side are legs linked to faces of gears with fulcrum on the body, and all gears per side are linked to spin same direction with middle leg 180deg out of phase, that's my final answer.