Blue Tits Nesting?

[virginia.c]

Back in May we put up two bird boxes. They were made by a twitcher friend who apparently made the entrance holes the right size for blue tits. Over the last couple of weeks I have seen a couple of bluetits looking in and today I saw one behaving like a woodpecker. It was hammering furiously around the entrance hole. I wondered if it was because it was too small but a few minutes later it emerged comfortably. Why the sudden activity? It wouldn't be nesting now - was it just checking out a possible new home for the Spring?

[Bob T]

Ours hammer at the holes on the boxes all the time. They must be getting bigger with all the seeds that they are eating! Ours nest twice a year.