For air to move there must a path hole in the ceiling crack in the drywall poorly sealed attic scuttle etc and a difference in pressure.
Difference between attic and scuttle.
Don t forget to also insulate the attic hatch.
A scuttle attic is an attic space accessed only by a small hole in a ceiling or less commonly a wall.
Probably a bird or squirrels.
You can buy some poison to kill the squirrels or rats in a garden centre don t let them stay up there as they can do lots of damage to the wiring etc if they remain.
Check this out for more info.
If ductwork is located in the attic make sure to insulate it as well to reduce heat loss and gain while passing through this unfinished space.
The bird will die after a few days if it can t get out.
This means you should insulate between and over the floor joists.
As nouns the difference between hatch and scuttle is that hatch is a horizontal door in a floor or ceiling or hatch can be the act of hatching while scuttle is a container like an open bucket usually to hold and carry coal or scuttle can be a small hatch or opening in a boat also small opening in a boat or ship for draining water from open deck or scuttle can be a quick pace.
The goal with an unfinished attic is to seal it off from the main living space below.