These robots are super cool. They self-organize to form a team in order to accomplish a goal that none of them could perform individually. The best part is they do it without being told specific instructions. They are modeled after "swarm" type insects (ants, bees, etc). In this case they are "rescuing" a child. While the practicality of these specific robots may not be all that useful I can imagine LOTS of scenarios where a swarm of robots can be used to provide services.
Someone fell through the ice in the lake... dump a few dozen diving robots in the water and they will communicate with each other and organize a search of the treacherous underwater scape in order to find/pull to safety someone in danger. Obviously that is just one example, but you can see how something kile this might be very effective.