Humans who already have mental issues consider it to be an act of divine cleansing and go around forcing everyone to see them.Regular humans commit suicide on visual contact.

Humans get affected only if you see them.So enough hints are dropped in the film to suggest demons. You’ve got the Puca from Celtic mythology. You’ve got the Surgat from ancient Christian occult beliefs that made pregnant women encounter their unborn children as other creatures such as lobsters or spiders. You got the Aka Manah, the various Daevas from ancient Zoroastrian legend. But it’s not indeed the end, which is what Bird Box is about. In this film, the apocalyptic end of humans (and perhaps animals) comes in the form of self-destruction. We’ll get to how these drawing got made later on, but these look like various images of demons from hell. While we are never directly shown what these creatures look like, there is a scene well into the film where we see drawings that could possibly indicate what the monsters are. Most people die, and the survivors need to blindfold themselves so that they don’t end up killing themselves. There is no rhyme or reason to the arrival of the creatures all over the world, but the wave of suicides begins in Russia and quickly sweeps the whole world. And it has come in the form of creatures who instill so much anguish and despair that it makes people commit suicide by merely looking at it.

How does tom die in bird box