A game that two of my lads did some years ago was to hang a variety of objects at different heights from the washing line. (although not good for a puppy perhaps as too much exercise jumping up whilst their bones are still soft might not be good for them).
Anyhow, it all seemed harmless enough until I discovered they had also superglued biscuits to the line and the poor dogs were both exhausted and demented trying to get to them.
Lads were grounded for a week.