And Josh Malerman admitted on Monday that it was the drama's unanswered questions that spurred him to write a sequel, which will be set eight years after the original.
The author, 43, revealed to Esquire: 'At the end of the movie, I turned to my girl Allison and said, "I want to know what happens next!" and she's like, "Well, you know, you could make that happen", so it really was this warm feeling.
'They've left there, [It's] similar in that they're trying to make things work. It's not like it opens with them in paradise.'
The acclaimed Netflix post-apocalyptic horror - based on Josh's 2014 novel of the same name - follows Sandra Bullock's character Malorie Hayes.
In the intense drama, she struggles to survive with her two children after the world is threatened by unknown energy which forces people to take their own lives when they see it.
Josh explained that while he's aware some fans were keen to know more about Malorie's children, named simply Boy and Girl, he wanted to focus on Malorie's story.
He explained: 'In the time between Bird Box coming out and the time since I've been writing Malorie, I've been asked a ton of times: people want to know what happened with Boy and Girl.
'But as much as I care about Boy and Girl, this isn't their story. The Bird Box world is Malorie's story and I wanted to know more about her. I wanted to get to know her even better.'
Netflix announced earlier this year that 45M subscriber accounts have already streamed Susanne Bier's zombie-style thriller.
'Took off my blindfold this morning to discover that 45,037,125 Netflix accounts have already watched 'Bird Box' — best first 7 days ever for a Netflix film!' the company wrote in a tweet in December featuring a GIF of lead actress Sandra Bullock saying: 'Oh my god' as she pulls off her blindfold.
The announcement is one of the first times Netflix has publicly shared viewership metrics, splitting from its tradition of keeping numbers under wraps.
Malorie is set for release on October 1 this year.
- Daily Mail
