Headscratchers / Suspiria (1977)

• Why did one of the witches cast a spell on Suzy in the first place? What was the reason for it?
  • The spell cast by the cook was to make Suzy violently ill, so that they could move her into the school and out of Olga's apartment while she was too sick to refuse. Suzy was a witness to events that happened the night Pat died, and they wanted her close to keep an eye on her.
  • Or more superficially, they were annoyed that Suzy was so presumptuous by refusing to stay at the school. They probably want all the students there so they can control them. Olga is the exception because she lives in town.
  • Olga's actress says she thinks Olga is a budding witch, so she's working with the teachers.

• What's with the bat? Did the witches send it to kill Suzy? Unlikely, it couldn't even get in until she opened the window, and she was supposed to be passed out at the time. Did they know she had dumped out the drugged wine? Also unlikely, after killing the bat (and how was one bat gonna kill her when she's wide awake anyway?) she's able to wander around and no one's the wiser. Did they think the bat had killed her? No, Madame Blanc is ranting about her need to die when next we see her. Honestly, it just seems like Suzy was randomly attacked by a bat. Girl has the worst luck.
  • The bat could just have been a random attack. We've seen that Daniel's dog seems to go mad when he's near the witches - not just barking a lot, he actually attacked Albert - so maybe all animals are affected by their magic whenever they cast. They were planning a spell to get rid of Suzy so maybe the bat just had the bad luck to be flying by the school at that time.
  • The additional lore in Inferno (1980) possibly answers this, Varelli's book explaining that the Three Mothers' houses have become so corrupted by evil that they contaminate even the land they stand on with death and decay (quite probably also explaining how freshly-delivered food came to be heaving with maggots so quickly). The bat may well just be channelling the evil infused into the building itself.

• What was the point of the maggots?
  • The maggots served to get all the students out of their rooms, allowing the teachers to search them. They know Pat was talking to someone as she left, and wanted to find out if there was any evidence left behind. There's one teacher who says that only the floor with the students' rooms is affected, confirming that it was a plot to search the rooms. That's when they find Sara's notes and realise they have to get rid of her too.