Adam; Sounds like a Wood Wasp. Perfectly harmless.
Check this out:
http://upload.wikimedia.org/wikipedia/co...
Like this?: http://pestcontrolcanada.com/INSECTS/bym...
That's a wasp.
sure it's not a DRONE? did you get photo of it? if not, try to if it comes back, post on photography sites like flickr & popular photo mag or instagram, then ask for replies
It is creepy.it's got 4 Orange legs a black body with white pokadots a long black tail with white rings round it attached to it looks like three strands
of wire it has 2 wings about 1 & half cm long it's got the face of a small wasp.
