Just like bugs (or geckos!) they are able to pull many times their weight.

It's all about timing, say the researchers from Stanford University responsible for creating the incredibly strong microrobots above. If you want to move large weights with tiny bots, they say, it's better to concentrate on precise movements executed in perfect harmony, than powerful single tugs. With this in mind, the scientists from the Biomimetics and Dexterous Manipulation Laboratory (BDML) were able to use just six of their 17-gram microTug robots to pull an 1,800 kg car.

"By considering the dynamics of the team, not just the individual, we are able to build a team of our 'microTug' robots that, like ants, are superstrong individually, but then also work together as a team," David Christensen, a graduate student from the BDML lab told The New York Times. He added that the demonstration above (which used his car, with him sitting inside it) was roughly the equivalent of six humans towing the Eiffel Tower.

...

The BDML's microTugs aren't just strong because they work together, though, they also take advantage of the science of biomimicry — replicating attributes from the animal kingdom. In this case, that means copying the design of geckos' feet to create spiked, sticky pads that the bots use to get a grip. The lab has previously used this technology to create even tinier robots that can pull objects 2,000 times their own weight.

Biomimicry sounds like a promising area for development!

Some Reddit comments have only just begun:

https://reddit.com/r/videos/comments/4aetj1/team_of_µtug_microrobots_pulls_a_car/

https://reddit.com/r/videos/comments/4afzi4/6_micro_robots_weighing_only_100gms_pull_a_2ton/