Clever Creatures of the Night by Samantha Mabry

In this gripping literary horror, Case's best friend Drea goes missing, forcing her into a bizarre, cultlike-and possibly murderous world-perfect for fans of The Honeys and Mexican Gothic.
Something bad happened here.
When Case arrives at a run-down, ivy-covered house tucked deep in the West Texas woods, an ashy haze lingers in the air and the sky is tissue-paper pink. Her best friend Drea has been living here with a few classmates Case has never met, and Drea asked her to visit in a letter dated two weeks ago.
But now Drea is nowhere to be found.
Drea's roommates can't-or won't-answer questions, leaving Case to search alone. She finds bits of Drea's journal hidden in the tiles of the bathroom wall, in a beat-up cooler by the muddy river, wedged into the frame of her closet door. As Case pieces together Drea's life in this strange house, the roommates' behavior puts her increasingly on edge-and she's not the only one. The animals nearby are lashing out, attacking each other, threatening the humans.
Something bad happened in this house. Something that must be connected to Drea's disappearance. And if she gets too close to the truth, Case just might be next.