Continuity mistake: When Ivy finds Lucius stabbed on the floor, she is wearing a clean white dress. The dress remains white even after she is rushed away by Mr. Walker. In the next scene, Ivy's dress is covered in blood near her waist, as if Lucius' blood got on her when she bent down to his aid.
Other mistake: The morning after the creatures give warning, the camera pans across the village. To the right, just left of the school, is the house where Lucius is put after he is stabbed. Notice the two smaller windows to the right of the door. Fast forward to the last scene, Noah's parents are sitting on the left and behind them you get to see the window frames are larger than the windows seen from outside. My guess is that the windows were bricked up so there would be better lighting for that scene.
Revealing mistake: When Ivy is running along the path in the woods, right before she bumps into the wall there are two large tree branches lying in her way. She shortens her steps and hops over both of them, even though her walking stick never touches them and she should have no indication that they're there.
Continuity mistake: When the two villagers throw the slab of meat on the rock for the creatures, it lands rib side up. A second later the meat is shown from a different angle, and now it is lying skin side up. (00:38:05)
Continuity mistake: When Ivy and Noah have a foot race to the resting rock, they run toward the house off the right a little, but the resting rock is way to the right, off camera, when they round the corner you can see the house they ran past probably more than a 100 meters away. If you notice the layout they are probably running toward the direction the cemetery.
Continuity mistake: Noah is sitting on the porch after stabbing Lucius, in the background is the house where Kitty and Ivy are talking about the marriage, it has a lantern on only to the right of the door. Presumably moments later Kitty and Ivy emerge from the house and suddenly there is a lantern to the left of the door as well.
Continuity mistake: When Alice Hunt speaks to Lucius at home after his request to the Elders, he is holding a skein of yarn as she winds it into a ball. As the shot changes to his back, and he gets up to open the box, all of the yarn disappears. He is not holding any, the length of yarn across the table has disappeared, and when Alice stands up, there is no ball of yarn or any other yarn visible.
Continuity mistake: When Ivy was talking to Lucius about how her older sister is spoken for, and how she is free to receive interest, her hand is on the other side of the pillar from her. When the angle changes, her hand is wrapped around to the front and she is almost hugging the pillar.
Continuity mistake: In the scene where Lucius first goes into the woods, he picks a branch of berries off of a bush. The size of the branch and the number of berries on it is different when he is walking out of the woods. There are more berries and the branch is bigger than when he picked it. (00:26:50)
Continuity mistake: While saving Ivy, in one shot Lucius is shown beginning to let go of Ivy's one hand, and in the next shot, they are running and he is holding her other hand. The cut was too quick for them to switch hands.
Plot hole: After Noah stabs Lucius, Ivy is brought to see Noah who is locked up in the "quiet room". As they leave, the lock is being placed on the latch to lock Noah in, and soon after the door is rattling, presumably Noah in an attempt to open it. If you look closely, you can see that the rattling occurs because the door lock is locked and not because of the lock on the latch. Quite strange, as we clearly see the lock placed on the latch right after the door is closed. There could not possibly have been time for the door lock to be locked with a key.
Revealing mistake: There are several scenes in the movie where the shadows of characters can only be created by using spotlights. (i.e. When Lucius and Ivey are walking back to Ivey's house after Lucius has crossed into Covington Woods, look on the left of the screen at the house, you will see the shadow of a chair, and the shadows of Lucius and Ivey. Also, when Ivey is sitting in Covington Woods under her tarp after the two boys have abandoned her, the spotlight is coming from the right of the screen.).
Revealing mistake: In the scene during Ivy's sister's wedding ceremony, right after the people all notice the boys screaming "Mr. Walker, Mr. Walker" Ivy is walking with her arm extended in front of her to find her way through the crowd of rushing people. At one point she has her hand right in front of a man's face (he has a beard and mustache), and despite being blind she then brings it up over his head and behind him in perfect timing without ever touching him. (00:14:15)