by Christoph — You've prob­a­bly heard of spi­ders that fly withtout wings. They climb onto flow­ers or leaves, stand on their tip­toes, and push gos­samer threads of silk from their spin­nerets, glands in their ab­domen, and take off. They do that to reach a nearby twig when weav­ing their webs or to make long-dis­tance flights, some­times over...