Mystery bird

Mystery bird

Observation - Mystery bird. Description: I heard a knocking sound from this dead tree, and a lttle face appeared in one of the nest holes. Hole about diameter of a £2 coin. The bird has a very small beak, so I'm thinking a Tit, or perhaps a newly arrived Swallow. I've enhanced the image as best

I heard a knocking sound from this dead tree, and a lttle face appeared in one of the nest holes. Hole about diameter of a £2 coin. The bird has a very small beak, so I'm thinking a Tit, or perhaps a newly arrived Swallow. I've enhanced the image as best I can to show the critter.