Love this thread... no trolling, no-one making stupid assumptions and being rude to other posters...
We put up a box last year with a camera in, it wasn't used and the camera failed so we took it out to get it repaired and I forgot to put it back... rather typically it's definitely being used this year, but I've no idea what's in there!
We get a lot of birds in our garden, there's always a pigeon or two wandering about, loads of tits, robins and sparrows, but recently we've gained a crow which I thought was really greedy until I realised it wasn't actually eating what it was picking up, so presumably there's a nest nearby