A close-up view of sex, bug-style, as David Attenborough talks viewers through the different ways in which creepy-crawlies reproduce. Size matters for the minuscule male orb spider, creepily sneaking up on its intended and trying to mate without her noticing, while there's no rest for the lothario-like butterfly, which has plenty of notches on its proverbial bedpost. However, the harvestman spider has no use for sex at all, and reproduces by cloning itself.