Don't forget cats. My mom moved in with us, due to her failing health, and for the remaining 12 years of her life, with her big, old, devoted Maine Coon cat. When mom eventually passed, the cat would still come and sit under mom's chair at the dinner table, where she always sat, hoping to get a *scrap/treat* from mom. Call it habit, but there was little we could do to bring this beautiful animal out of her grief. Although we tried. About a month later, we found her cat dead, curled up in a sleeping position, under the chair, at mom's place at the table.
Call it anthropomorphic, habit, I don't know. But it happened.