Only tits, but some surprises.

There's a Great Tit pair nesting on the ground a few metres form my kitchen, down inside a couple of hollow concrete blocks. I feared they were feeding the young on bombay mix some idiot had put on a bird table nearby. When I looked with the bins they were dried mealworms!
Other food they bring looks like seeds, etc. though, which doesn't seem a good idea.

The Blue Tits even nearer the window, by contrast, are bringing fat green caterpillars to their 8 young up till 9.15 pm. Their box I made by hollowing out the top of a tall stump of a pine I had to cut down as it was lashing the windows upstairs. It's been used a couple or three years now, so is a bit soft. A woodpecker has been having a go at getting the young. It got some of the nest material out this morning, so I split a black plant pot and wired it round the damaged part. The adults accepted it emmediately, continuing to feed without hesitation. I know the woodpecker has to feed, but I felt guilty giving the tits an insecure box.

Another box down the garden has just 2 well-grown Blue Tit chicks in it, sitting on a pile of unhatched eggs!