Fact of the day: Which insect has the shortest lifespan

We humans usually get several decades on this planet, yet we constantly complain that life goes by too fast. If you ever want some perspective, just look at the mayfly. As adults, many mayflies live only a few hours to a day, although some species can survive for several days. Try to picture cramming your whole adult life, finding a partner and starting a family, into the exact same amount of time it takes a normal person to work a single shift and drive home.Why do they drop dead so fast? It really just boils down to extreme biological efficiency. Once a mayfly actually earns its wings, it enters the world without a functional digestive system or even a working mouth. Seriously, they physically cannot eat or drink anything.Instead of a stomach, their digestive tract is essentially just a pocket of air, which helps keep them lightweight and aerodynamic for flying. Evolution gave the adult mayfly one job only- reproducing. To pull it off, they survive entirely on energy reserves they stockpiled when they were young. Once they manage to mate in mid-air and the females release their eggs into the water below, the gas tank is completely empty, and they simply die. But here's a detail a lot of people miss: a mayfly isn't actually a one-day wonder if you look at its whole life cycle. The process is really a long, incredibly patient waiting game that just happens to end real quick.It starts with tiny eggs sitting on the bottom of freshwater lakes and rivers. After hatching, they become aquatic "nymphs," and they actually hang out underwater for quite a long time, sometimes up to two whole years. They spend all those months peacefully eating algae, breathing through their gills, and trying not to get eaten by fish. It’s only when mating season finally hits that they swim up to the surface, shed their skin, and take to the air for their last day on earth.The Double Molt: They hold a completely unique record in the animal kingdom. Mayflies are the only insects on earth that shed their skin (molt) again after they already have fully functional wings.Summer Snowplows: It gets even crazier in towns located right next to large rivers or lakes. The aftermath of these massive swarms can leave dead insects piled several inches high on streets and bridges. It gets so extreme that local officials sometimes have to fire up the snowplows in the middle of summer just to scrape the roads clean.Even the scientific name for their order, Ephemeroptera, tells you exactly what they are, it translates directly from Greek as "short-lived with wings."