This week, we look into new ways of putting a tiger in your tank! We find out how pond life could help make eco-friendly biodiesel and how new types of batteries can power electric cars for further than ever before without running out of juice. Plus, how Margaret Thatcher's face can tell us how monkeys recognize each other, what sharks have in common with serial killers and why dolphins are a bit like jet fighters. And in Kitchen Science, we see how batteries work in Arctic conditions. Like this podcast? Please help us by supporting the Naked Scientists)