According to director M. Night Shyamalan, 85% of this movie takes place outside.
The film took 44 days to shoot, which began on August 6, 2007. This is exactly eight years to the day since the start of production of The Sixth Sense (1999).
The movie was shot completely in sequence.
Bystander Apathy is an actual psychological phenomenon with a strong theoretical and evidential base.
Pyrethrins are a neurotoxin derived from the Chrysanthemum plants, specifically those native to Australia. This toxin is commonly found in common organic insecticides to eradicate pests. At one point Elliot talks about primordial bacteria in Australia killing off fishermen. Pyrethrins are highly toxic to bees.