When Tyler goes out to the unheated shed and finds the dirty diapers, you hear flies buzzing. This movie is in the middle of winter with snow on the ground.
M. Night Shyamalan personally financed the film so that he could have complete creative control over the final product. He wanted to make a low-budget, back-to-basics movie, as he had just finished working on a string of high-budget critical and commercial failures (including "After Earth" and "The Last Airbender") where he had little creative control due to the budgets and studio-mandates. It paid off, as this film, his next film "Split" and his television series "Wayward Pines" were generally considered a "return to form" for Shyamalan by critics.