Science: Why insects circle lights, turning animals off plants

Science correspondent Allan Blackman joins Kathryn to talk about new research into why insects circle lights at night - is it time for humans to flick the off switch? An Australian study has looked at how herbivores can be encouraged away from valuable plants using odours they don't like, and it's the anniversary of the passing of Kiwi scientist Alan MacDiarmid - Allan celebrates his contribution to chemistry. Allan Blackman is a Professor of Chemistry, School of Science, Auckland University of Technology.