Mosquitoes, bats, and even eels use non-visual means to sense their environments. For mosquitoes, part of their obstacle avoidance comes from the exquisite sensitivity of their antennae, which are able to sense subtle changes in the air flow around them as they approach a wall or the ground. Researchers used this same technique to help a quadcopter avoid crashing by adding air pressure sensors that respond to the changes in the copter’s wake as it approaches the ground. (Image and research credit: T. Nakata et al.; via Science)