How does each family member react to Gregor after his transformation—what is different and similar about each reaction?
In Kafka's The Metamorphosis, the reactions of the family members is different and similar.
When it is discovered that Gregor has changed, at first his sister, Grete, is the only one that comes to his aid:
Gregor, aren't you well? Are you needing anything?
She tries to find foods that he will like:
...old half-decayed vegetables, bones from last night's supper covered with a white sauce that had thickened; some raisins and some almonds; a piece of cheese…
Grete talks to him and she still seems to care for him, however then she becomes controlling, claiming Gregor's care as her individual right, even though she is not committed to helping him in doing so. She gets a job and cares for Gregor, resenting her mother's attempts to help her brother—but then she finally detests Gregor and insists that they get rid of him.
Mrs. Samsa is overwrought by what has happened to her son.
Do let me in to Gregor, he is my unfortunate son! Can't you understand that I must go to him?
She tries to be supportive, but cannot bear to look at him. Entering his room ends up being too difficult for her. She tries on several occasions to defend Gregor, in maintaining that he should have his furniture when Grete wants it removed, and trying also to stand up for him when Grete suggests they get rid of him, but she is too weak and becomes ill. Though she cannot look at him, it seems she still has a mother's love for him.
Mr. Samsa is cruel and angry. Of all of them, he is the one who has most become used to Gregor working so hard and handing them his money so that they may all live a life of leisure while Gregor continues to support them. It is when Gregor can no longer do so because of his metamorphosis, that his family begins to reject him.
Gregor's father is the one who becomes violent. When Gregor first leaves his room, Mr. Samsa's behavior (waving a newspaper and a cane and making noises) frightens him so that Gregor pushes himself through the narrow door to his room, scraping himself and harming parts of this "body." When the women try to move Gregor's furniture out, Samsa believes Gregor has done something terrible and begins throwing apples at him: one that painfully lodges in Gregor's back.
An apple thrown without much force grazed Gregor's back and glanced off harmlessly. But another following immediately landed right on his back and sank in; Gregor wanted to drag himself forward, as if this startling, incredible pain could be left behind him; but he felt as if nailed to the spot…
Mr. Samsa and Grete don't have a problem with Gregor until he is no longer of financial use to them. Ironically, before Gregor's "illness," Grete is considered something of a waste: she does nothing. When Gregor is changed, slowly she becomes the favored child. By the end, she becomes more "valuable," as the family, released from worries about Gregor, goes out for the day and realizes that Grete is of an age to marry. It is not for her happiness that the family is pleased, but more because she will be able to find someone else to support the family while they continue to live a life of leisure. Though Gregor appears "monstrous," his family members are truly the parasites. By the end of the story, Grete and Mr. Samsa want Gregor gone. Mrs. Samsa cares for her son, but cannot stand up to Grete.
Gregor dies alone and detested: had he been able to go to work as a giant insect, I expect the family would have been able to tolerate him.