I bought an RSPB bird box with camera many years ago and this year I finally had a pair of blue tits nest in it and typically ... the camera stopped working. I managed to get and fit a replacement without disturbing the birds, She laid 9 eggs but I think only 7 have hatched but it is fascinating watching them, so much so that I set up another external camera to film them entering and leaving the box. Here is one of the videos that I put together
https://youtu.be/ucUaBUG06Kc