Reminds me of what a mate & I did some years ago as kids....
Woman next door to me would not allow tradesmen, etc into the house while her husband was away all week at work...thus her delivery of a sack of potatoes had to be left on the front porch, and until her husband returned on the weekend she would take some in for each day for the evening meal.
She was one of those well to do busy bodies who knew everyones business, including ours, for which we often we copped disciplinary measures, due to her say so....hence a plan was hatch for some well deserved payback.
One particular evening we put one of those artificial dog turds on the sack of potatoes and hid behind a hedge in her front yard to witness the commotion....and sure enough, there was one, to which we could not contain our laughter as we retrieved the plastic turd from right under her nose.
Aw c'mon, ya didn't think it ended there, did ya? About a week later, armed with a piece of perspex, we scoured the village for a real 'live' dog turd to put on her sack of spuds. After conveniently placing it just as before, we took up our positions to enjoy the greatest gag of our lives.
Upon finding the 'live turd' and hearing us erupt into uncontrollable laughter, Mrs Murray announced: "You little buggers aren't going catch me again." and promptly picked it up herself.
The embarrassment must have been more than she could cope with because, despite it being the worst thing we'd ever done, to her or anyone else, she said nothing to our parents or her husband.
Not bad for a 7 and 8 year old, hey!!!