Characters » Kurosuke Makkuro
In My Neighbour Totoro, the house the main characters move into is full of Susuwatari, which are rationalized as Makkuro Kurosuke (pitch-black blackie), an optical illusion caused by moving quickly from light into darkness. Later, the family drives the Susuwatari out of the house, as the home that was once abandoned is now inhabited. They would move to another abandoned area.
In Spirited Away, the protagonist Sen (Chihiro) befriends a number of them by helping them carry coal. Sen is told that if these Susuwatari aren't given a job to do, they turn back into soot. Another character, Lin, feeds the Susuwatari much like farmers feed chickens, throwing handfuls of the Japanese candy Kompeito onto the ground for them to eat.