No I'm familiar with those - had it before in the previous house. Pretty sure its some sort of insect nest.
I'll investigate a bit closer tomorrow if I'm feeling brave, and if it doesn't eat me in the night.
I know there is every kind of expert on this forum...
I just went up in the loft and noticed a green glowing 'light' that wasnt there before. On closer inspection (well not too close) its some sort of insect nest. What the hell kind of insect is it?
Its quite bright - a similar luminosity...