Jumping Spider, Salticidae

Quite possibly the cutest spider family is Salticidae, or Jumping Spiders. If you can get close enough to watch them properly, they're hilarious. They constantly hunt and generally seem to try and jump anything up to about house fly sized. ..And man can they jump! Over 30 times their own body length - the equivalent of me jumping 52 metres from a standing start! They're able to do this because they have an internal hydraulic system. This allows them to rapidly change the fluid pressue within their limbs, producing a "snap" leg extension to propel them further without relying on muscle alone...They're also a lot more romantic than you'd expect - a male will sing to a female when he's trying to get it on. And very politely he'll ask if it's quite alright with her, by touching her with his front legs to check she's not thinking of making a run for it. That's her last chance though - after that, he'll use his larger size to make sure she isn't going anywhere.