Steve Caplin on the latest tech. VW have developed a kangaroo scarer for cars. A home security device can fire paintballs or tear gas. There's a three-legged robot for asteroid mineral extraction, a two-legged humanoid that can be trained remotely and a drone that can hop on one leg. Skateboards can now be propelled by an expensive broomstick-like device. The Post Office can't tell if its own stamps are counterfeit or not. A crow near a police station can imitate two types of siren. And Elon Music wants to send 1,000 rockets to colonise Mars.