how does the family take care of gregor and his room

THey pretty much lock Gregor in his room. Grete, his sister, is the only one in the family with whom Gregor was intimate. At first, she takes it upon herself to clean his room and feed him. With time, however, she loses interest in this and leaves him alone. Grete brings bug food for him and shoes it in the door. She moves furniture around for him as well.