Posted: 29/11/2012 at 18:47
Thanks everyone for replying.
I've seen them on and off in varying numbers over the last few weeks but it was the massive number of them I noticed today that started me wondering. I've had a closer look and done some 'prod testing' and I think they must be some sort of polystyrene packaging... that said they seem a little heavier than I'd expect polystyrene to be but they are pretty uniformed in consistency, texture etc throughout.
I'll get the car-vac on them and see if they come back... if they do it's either a very strange type of egg, or my neighbour tipping their rubbish!