Oh, he is just so naughty! He has most of one of the bedrooms here for his big pen, with stuff stored around the walls(our junk room). So, before I got up this morning I hear what sounds like clinking chains.
Go have a look and here are 4 stainless steel chains, plus the remains of a plastic bag they were in. Couldn't think at first what they were, then realised they were bench chains from when we showed dogs at the Royal Melbourne show. I would not have been able to find them but he DID, and how he reached them I'll never know, ditto for how much of the plastic bag he has ingested. I had to clean his entire pen, with his paper shredded like confetti, (so he can 'bury' his beef bones), looking for the remains of the plastic.
Lindapalm, good suggestion about putting the top of the birdbath on the ground, better than what a friend here suggested, hot wiring it.
He's got a pool but in the depths of Winter it is out of bounds.