In message , Mary Fisher
writes

"Gordon H" wrote

the last time blue tits nested successfully in one of
my nest boxes, there was a real battle between the tits and a large bumble
bee which tried to claim the box, so there could be something in the
theory, though the material they used was softer than straw.

Usually the birds will win. Wasps sometimes take up a tit box too. It's
fascinating bcause the space needed by the wasps is larger than the box so
the paper nest is extended outside. We once had such a box, it becme totally
engulfed inside the enlarged nest.

Mary

A neighbour came to my door to warn me that wasps had taken over her
nest box, and to check mine. I knew they were empty, but I could
picture a wasp nest enveloping a box.
--
Gordon H