What's killing the bees?

It is that time of year again when we should start to see bees buzzing around gardens but populations of bees have been declining recently as disease and lack of food stores are hitting them hard. With a third of global food supply coming from crop species that are to some extent dependent on bees it's important that we halt this decline. Felicity Bedford went to Cambridge University's King's College to meet Kristen Treen, who looks after the honeybees there, and see how their beehives have been getting on this winter Like this podcast? Please help us by supporting the Naked Scientists