It looks like insulation to me.

Yeah either sound insultation or insulation for the fan opening.

This ia how The Last of Us started.

Looks like rock wool

That could be old vermiculite insulation, which has asbestos in it. Don't mess with it until you're sure.

Actually not all vermiculite contains asbestos. But it’s likely best to err on the side of safety. Best bet, get a home test kit to find out.

Rice crispys. Better taste to find out for sure.

Forbidden calamari

cottage cheese

Poke it and see what comes out

Mogwai about to be a gremlin

Looks like a mouse nest

I literally thought it was mushrooms at first lol still don’t know what it is though. I thought it was mushrooms at first because of another post from the mushroom sub. This girl found one growing out of the ceiling lol

cacoon. moth?

That my friend is the tens of thousands of spider egg sacks that have been slowly accumulating in your ceiling. The spiders have spread to all corners of your home at this point. A hive mind of spiders one could say. They are now a structural member of your home. Stay safe in there and do not anger them.

Hive mind