- Narrator: Cassie
The Yeerks hatch a plot to level the national forest where Ax and Tobias have been living.
Tropes:
- Collateral Damage: When Cassie sees the mother skunk's injury, she recognizes it as a Dracon beam wound. She realizes it happened when she and Marco were fleeing the forest as wolves the previous night.
- Didn't Think This Through: Cassie nearly gets trapped in skunk morph because she fell asleep after feeding the kits. She only gets out because Tobias thought ahead and told Jake what she'd be doing.
- Eek, a Mouse!!: Cassie and Rachel nearly get stomped by a pair of punks while in rat morph. Unlike Darlene, who was just afraid of mice, these punks are jerks looking for something to break.
- Foreign Cuss Word: The Yeerk named their logging business the Dapsen Lumber Company. According to Ax, "Dapsen" is not a polite word in Yeerkish.
- Green Aesop: Logging is bad, as Cassie emphasizes. Cassie herself is frustrated by the fact that the rest of her team prioritizes their own survival over the survival of the forest, even as they're working for the same goal.
- Hive Mind: The termite morph manages to be worse than the ant morph because the Animorphs use it in close proximity to the termite queen. Even after regaining their human/Andalite intelligence, they're unable to control the termite bodies until Cassie tricks her termite instincts into seeing the queen as an ant and killing her.
- Named After Somebody Famous: Marco names the skunk kits Joey, Johnny, Marky, and CJ, reasoning that their hair stripes means it's only natural.
- Nature Is Not Nice: Cassie's love for nature and all living creatures has been established, but it's the first time it occurs to her that nature itself doesn't care if the creatures living in it suffer or die. When she makes it her mission to rescue the skunk kits, she gets their location from Tobias. It takes Cassie a few seconds to realize why a bird of prey like Tobias would know the location of a skunk den, and she's furious with him for it, despite the fact that she knows he needs to hunt to survive.
- Obstructive Bureaucrat: Something that works in the Animorphs' favor is the fact that the Yeerks don't control the government (yet). This means that their operations can get bogged down by red tape and media attention. They usually solve the problem by infesting said bureaucrat, which nearly happens to Farrand, who gets rescued by Cassie.
- Screw the Rules, I Have Supernatural Powers!: The Yeerks go ahead with the logging operation without the tiebreaker vote from Farrand because they can just infest him once he arrives. Unfortunately for them, Farrand is rescued by Cassie and gets back to civilization where he reports the operation as illegal, shutting them down.
- Smelly Skunk: The entire team, except Tobias, acquire skunk morphs in this book.
- Homer is the first victim of getting skunked, as Cassie doesn't recognize him except as a potential threat to the kits.
- In one of his more inglorious moments, Visser Three gets sprayed when he thinks he has Cassie cornered. It forces him to disengage and let her and Farrand go in exchange for learning how to get rid of the smell.
- Some Kind of Force Field: The force field around the logging building gives away the fact that this is a Yeerk operation to Tobias. If it gets projected over a solid object, the force field casts a shadow of sorts, allowing the Animorphs to get underneath it as termites.
- Squirrels in My Pants: To save Courtney (the rat they acquired) from the teenage punks, Cassie and Rachel run up the pants leg of one of the boys, causing both of them to panic and flee.
- Tomato Skunk Stink Cure: Visser Three gets skunked by Cassie in morph. The Visser has them cornered, but Ax points out that the smell is going to linger, and that returning to his spaceship (an environment not known for being easy to air out by opening a window) will only transfer the smell and require a weeks-long cleaning at a major space station. He lets them go in exchange for the secret, and the book ends with Tobias reporting the Visser is now a lovely shade of purple, and the Animorphs musing that they should maybe have told him he should bathe in tomato juice, not grape.
- Troll: The Animorphs tell Visser Three that grape juice, not tomato, will get rid of the skunk smell. The human-Controllers who know better keep quiet out of fear of contradicting the Visser.
- What Happened to the Mouse?: Literally. Courtney escaped the science lab after the punks ran away; Cassie hopes she's living well somewhere in the school walls.
