Good movie, interesting choice in plot twist.

Don't get me wrong. The movie was great. Acting, music, plot, all of it. However I want to point out the girl didn't just kill off humans but her own species as well. As we can learn from observing any environment, if a balanced ecosystem is not in place the whole ecosystem as a whole suffers. Like any carnivore, if their number becomes too great, their food becomes more scarce. Ultimately leading to the death of the prey's species if not reset. Humans were scarce in the movie already. Resigned to protective facilities to survive and there number dwindling as the movie progresses. Throughout the movie we find out these "zombies" rnt dead at all. But alive. They each have a fungus in their brain causing violent and carnivorous tendencies. And if there is one thing we know about these creatures, especially the children is that they need to eat to avoid becoming more violent. The movie doesn't explain what happens if the fungus symbiotes don't feed at all. But as with all living things it needs energy from somewhere to survive. Near the end of the movie they discover the second stage of the first generation of fungi. In this stage the fungi could became airborne. As a twist Melanie releases the airborne fungi into the air. Affectively wiping out all living creatures coming in contact and turning them. We don't know how the fungi affects animals but it is safe to assume animals will be killed as well due to this flawed decision. So this not only wipes out humans but any other source of energy to help maintain the growth of the fungi. Also the movie very clearly states the fungi don't feed on one another. So at the end of the movie Melanie has all the fungi children sitting down for class with the beautiful teacher Melanie has come to love. Fortunately the teacher was in an airtight room so she wasn't affected, but now these children's only source of substance left on earth is trapped in an airtight building that Melanie knows how to get in. Melanie is clearly the alpha child commanding the other children and protecting the teacher from becoming supper. It probably helps that none of the children can smell the teacher. The movie ends with a lovely scene where the kids are attending a kind of school to learn as Melanie has. But one has to wonder what happened after that sunny ending. Like vampires and their gluttonous feeding habits. One has to ask what would happen if vampires had drank every last drop of blood left on earth? They r already dead so maybe nothing, but these fungi r living beings with no source of energy left based on what info the movie has given us. So I fear for the lovely teacher after the credits have rolled. Not to mention the high probability that the rest of the world would become a barren waste land with no life at all. Including the fungi the girl sought to protect.