In the movie 'Leave the World Behind,' the presence of deer holds a deeper symbolic meaning. Director Sam Esmail explains that the deer are intentionally portrayed as menacing to create a sense of threat and turn the peaceful image of deer on its head. Esmail wanted to take something typically seen as harmless and use it to convey a warning to the characters and the audience. The film uses CGI deer to make them feel as real as possible. The appearance of the deer throughout the movie serves as a visual representation of the impending environmental crisis and the destruction of animal habitats due to climate change and other disasters. The deer symbolize the rapidly changing world and the idea that humans cannot control everything that happens to them. They serve as a reminder of the urgent need for empathy, cooperation, and reconnection with nature in order to overcome differences and address the climate crisis. 'Leave the World Behind' is available to watch on Netflix.
Source: [Digital Spy](https://www.digitalspy.com/movies/a46088647/leave-the-world-behind-deer-explained/)