In the scene where we see maggots crawling over a dead man’s body, the maggots were purchased form a fishing tackle shop the previous day. They were kept in the fridge in the provided container with sufficient ventilation. A large blue sheet was spread out in front of the camera. This was where the maggots would be placed. The film of those maggots was then digitally placed on the man’s face via CGI. Whenever we see ravens, they were also filmed on blue screen and digitally placed in the scene where we see the dead in the bomb craters.