Look at the Wren nest above that I found this evening. The pulse was racing with this discovery but would it be N4, NL or a nest record with eggs? Surely this piece of avian architecture is worth eggs! With record amounts of adrenalin pumping round the body I inserted my finger and - it wouldn't go in! It was a woody growth on the trunk with just enough moss on it to fool this nest recorder.
Two tit nests just started being built so check those empty boxes one more time. Also had a few just started to lay with many more boxes at NL ready for eggs.