Breakthroughs, discoveries, and DIY tips sent every weekday. A tiny robot fiddler crab is helping environmental scientists better understand the complexities of animal mating rituals and rivalries. And while their initial findings published August 5 in Proceedings of the Royal Society B are helping solve these ecological mysteries, the data was only obtained at considerable peril to'Wavy Dave.' Male fiddler crabs are engaged in a constant, literal arms race. The males are known for asymmetrically sized pincers, with a dramatically larger major claw compared to its smaller one. The reason for this sexual dimorphism is mainly twofold--mating and fighting. Female fiddlers generally opt for the male with the largest major claw, which the latter advertises by waving it at potential partners more quickly than his competitors.