Does dust stink? I think so.
Today, I cleaned the master bedroom, which contained a rather large quantity of dust bunnies. They like to breed in hard to reach places that are even harder for a third trimester pregnant lady with heartburn that gets worse if she bends over to reach. Still, I managed and the room smells a lot better. Maybe it's the dusting spray I used. Maybe it's the clean laundry I just put away. Or maybe it's because those bunnies aren't being cooked under the radiator every time the heat comes on.
Just think of what those bunnies are made of, especially since I have a dog. That stuff has to be stinky!
So, if your house has an icky smell to it, check for dust bunnies.