In February of last year I posted the news that I had installed some nesting boxes in my garden. They remained vacant last year but the latest news is that one is now home to a family of bluetits. I don't know how many there are but I have seen either mum or dad popping in and out many times. Today I was quite nearby when it happened and it had a caterpillar in its beak and I could hear the chirping of chicks in the box.
I don't think the other one has been taken yet. Maybe next year.