I've just taken down a nesting box that has been attached to a tree for two
years now. Over the two years I've seen quite a few blue-tits investigating,
but couldn't work out if they were actually using it. Anyway, it looks empty
and clean inside and I'm wondering if it's actually any good. The entrance
hole is 1 inch diameter and has obviously been pecked as if to make it
bigger and the inside space is tiny - only 2.5 inches from front to back.
The height is average box height. Is this box useless and should I buy a new
one? Blue-tits seem to be the ones most interested in a box.