Dryer exhaust, need advice.

[arewethereyet]

Is something inside it?  Maybe a squirrel or something found it's way in and can't find it's way out.

No, it isn't a roof exhaust port. It is a side port which also has cover so rain won't get in. It stopped now so it is most likely simply a difference in air flow' temperature between inside and outside.

If your dryer isn't running there shouldn't be any air flow in the duct.  And exhausts often aren't on the roof.  Squirrels find all kinds of ways to get inside.  Birds are also known to slip into them and make nests.

It was just an idea.  Maybe it's a ghost.  Hell, I don't know...just trying to throw some ideas out there.