There are 5 surviving great tit chicks out of the 7 that hatched. One died last week after a day, or so, out of the nest cup. Another must have also died as there are only 5 visibly active now. The parents have started to feed the chicks through the nest box hole, at times.

Great Tit Chicks Being Fed in Box 3

Great Tit Delivering Food to Box 3