Vigorous roll in the web can leave spider without a penis

Did you know that some male spiders copulate with such unbridled fury that the little spider penis breaks off inside the female? It's true. Researchers at the National University of Singapore have discovered that it really is a guy thing among a tropical species of orb-spider to castrate themselves — either partly or the whole magilla — after a roll in the web. Turns out it really isn't as self-destructive as we non-spiders might think, for as a new study shows, it makes them more virile, and the weight loss from the missing member makes them better fighters in fending off jealous male rivals.