Hi Bea. How revolting, I can understand why you are so upset.
Someone let their apparently very large dog mess right at the bottom of our drive in the middle of the pavement yesterday.
We are en route to various primary schools, so it could have caused a right mess with the little children and pushchairs.
DH flicked it into the road. Bleurgh 
Unless it absolutely stinks to high heaven, it’s unlikely that it’s foxes.
I think that you would have noticed it before.
Just a thought, I don’t really know about this, so I could be totally wrong - but if it’s HA, couldn’t the housing association or council do something about it?
And as there is such a lot of mess, is it a environmental health issue?
It doesn’t seem at all fair that you’ve got to deal with it.