“Why didn’t the family just live next to a waterfall?”

—serenafischer

“It took a CHILD to figure out high-frequency sounds harm the creatures? The military couldn’t grasp that? I still liked the movies, but they are FULL of plot holes.”

—Th3FatPanth3r

“Those parents had no common sense at all. Who just conceives a child in the middle of an apocalypse where you aren’t supposed to make any noise whatsoever? Did they just forget that babies cry a lot?”

—aries97

Writer’s note: The pregnancy plot sparked a LOT of discussion in the comments. Several commenters said that birth control probably wasn’t easily accessible during the apocalypse, but others pointed out that, since insulin was still available at the pharmacy, it would be logical for birth control/condoms to exist as well. That being said, no birth control method is 100% effective. 

HOWEVER. I went down a deep dive for this and found that John Krasinski (who played Lee) talked about the plot point on an episode of The Empire Podcast, and it seems the pregnancy may have been an intentional choice, partly motivated by the death of their child, Beau. “Some people split up [after a loss],” Krasinski said. “And then, the other version is you force yourself to move forward, and it almost becomes this recalibration of your entire life by trying to have another child. I think it’s somewhere in the middle [here].”

Source: https://www.buzzfeed.com/kellymartinez/horror-movie-plot-holes-and-questions