Cats are an invasive species in Australia, and are killing off the native species. This guy has a wildlife sanctuary of sorts in his back yard, which was discovered by feral cats. So he built a device to deter them from entering. This is not your regular dry DIY video. Sure, he built the device, but the rather entertaining story involves not only a water hose and arduino, but also Kentucky Fried Chicken, a suspected gas leak, yogurt, and polygamous kookaburras.