Posted: 17/07/2015 at 05:59
Are these 'your' hives or do they belong to another beekeeper ?
If they're yours I would consult with your local branch of the British Beekeepers' Association and see if this is happening to other colonies in your area .
If they belong to someone else you need to let them know that the behaviour of the bees is changing.
Just a thought, what were you wearing? - I remember in the past being told not to wear black around beehives because it makes them aggressive.