Kid from the diner (SPOILER)

OK, help me out here. So the kid's walking home through the woods, then there's a cutaway to suggest there may be a wolf somewhere in the same state. Then the kid falls down for no conceivable reason, rolls around screaming for a while, gets some inexplicable red stuff on her face (red tree sap dripping on her, maybe?), then dies.

So what happened? Did she trip and fall on an anthill and they tickled her to death? WTF?