Any fly experts?

[wattsy]

I keep finding these flies in the bowl of the toilet pretty much everyday, the window is always shut so I'm assuming they're in the wall cavity or loft (upstairs loo), I fished this one out for some pictures to take to the council if it's an infestation but I'd like an ID first if possible. It doesn't have biting mouth parts, something the picture doesn't show, so I think it's a member of Diptera but again I'm not an expert, or even an enthusiast lol (more of a butterfly fan).

Any ideas?

Cheers
Matt

p.s. scale is in millimetres

 

[EdS]

Its a cluster fly:

http://www.clusterfly.co.uk/site/index.php

 

[bushwacker bob]

The larval stage is dependent on the earth worm so once you have got them out of the cavities (smoke bombs) you will need to get rid of the worms in your lawn for a while.

 

[EdS]

you also need to clean well as they leave a pheromone trail and will return the following year.