The difference is pressure is most commonly created by a difference in temperature.
Difference between attic and scuttle.
This means you should insulate between and over the floor joists.
Check this out for more info.
The goal with an unfinished attic is to seal it off from the main living space below.
The rule here is simple.
A scuttle attic is an attic space accessed only by a small hole in a ceiling or less commonly a wall.
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.
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.
Probably a bird or squirrels.
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.
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.