Greenbottle (Lucilla caesar)
The Greenbottle rarely comes in to our houses and I confess that it is not the most tasteful of insects. Frequently seen on dung of all kinds, especially dog's, and then seen on Blackberries. Do you like to pick the odd blackberry to eat as you stroll along a country path? It lays its eggs in carrion and the larvae are a key part of the recycling process.
There are various similar species but, as far as I can tell, this is the commonest, Lucilla caesar.