Yesterday, I had the combination of this problem and another peeve - a cyclist on the pavement who, having gone past me, stopped a little further on, staying on his bike, and there was only one side, leaf-strewn, by which to get past him (it was a narrow pavement). So I stepped onto the leaves right onto the dog poo hidden underneath, and it oozed its way into the grooves of the tread on the soles of my shoe. I resisted the urge to rub the pillock cyclist's nose in it (I'm just a wimp so would never have done it).