Sometimes you are in the right place at the right time to see something that is unusual and which you may never see again. Continuing our flashbacks to the past, here is a post from April 2013 of a Nuthatch trying to enlarge the entrance to a nest box. Presumably fancied it as his des-res. Not seen since and the box has continued to house a Blue Tit nest each year.
Here are a couple of short video clips of the Nuthatch trying to get into nest box 2