I'm not sure if you've noticed it, but Bell and Salty have a special abilities that aren't like the others. They can sense happiness form people and pass it on to others.

When I first came here, I used to have nightmares too, and... I've always felt a little set apart and lonely from the others. After a few nights, Salty started sleeping next to me, and they started going away. Not to mention just looking at her always seem to cheer me up.