Bee In A Policeman's Bonnet

Policeman's helmet is one of the names for Himalayan balsam. (When I think of policemen's helmets I always think of Twickenham streakers  Michael O'Brian and Erika Roe. :) )  This exotic-looking plant was brought to the UK in 1839 as a garden plant but it is invasive and chokes up watercourses. Most of it has been removed from the banks of our neighbour's lake but there's a little clump of it left which the bees love.