For us it is foxes
Late one night I had the bedroom window open and as I was drifting off I heard one of our dog's squeak toys squeak in the backyard... but the dog was asleep at the foot of the bed- I looked out and there was a fox playing with one of her toy balls- tossing it around and squeaking it... it played just like my dog does... unfortunately they occasionally leave behind a mess to clean up- droppings or the partially consumed carcass of an unlucky bird...
They are graceful beautiful creatures, but their cry is bone chilling...
I have heard what the fox says, and it is deeply disturbing....