A science teacher is teaching girls beekeeping after putting hives on the roof of a school.

Dr Rob van Es launched the project to show pupils at Plymouth High School for Girls the science of honey making.

They will also learn to be industrious by making honey, and making money.

A group of about 30 girls take it in turns to tend three hives at the school, thought to be the only school with hives on the roof.

Dr van Es estimates there are about 150,000 bees living in the hives. He hopes to get 30 to 50lb of honey this year, which will go to the school canteen.

As the yield goes up in future years, the honey will be sold and the money put towards bee-keeping costs.

The girls wear protective equipment bought with a grant from the educational charity Ernest Cook Trust, which promotes the conservation and management of the countryside.

Dr van Es said the bees are a very docile strain.

He said: "There is no reason anyone should be stung.

"Bees really only sting if they're squashed."

Bees out looking for flowers tend to fly at well above head height, he said, so there was no risk to pupils or the public.