The great tits I filmed so intensively feeding their young inside a hollow concrete brick in the ruined Bofors Gun Pit, have now flown; the hatchings fledged and the nest abandoned until next year. I decided to take a look and found that the bedding of the nest was some five inches deep and seemingly built up over a number of years by subsequent generations of the bird. It is a soft warm carpet of mosses, feathers and tiny dried leaf fragments – as well as the skeletal remains of at least one tiny bird that did not make it. I carefully replaced the nest materials inside the concrete block and restored the small entrance to this tiny home.