Larvae in nestbox

Larvae in nestbox

Observation - Larvae in nestbox - UK and Ireland. Description: Trying to clean nestbox, found lid stuck down. Eventually managed to prise it off, this mass of ?pupal cases and silk, a few yellow larvae with brown heads crawling amongst it. Wood of nest box had been partially excavated by the cases.

Trying to clean nestbox, found lid stuck down. Eventually managed to prise it off, this mass of ?pupal cases and "silk", a few yellow larvae with brown heads crawling amongst it. Wood of nest box had been partially excavated by the "cases".