The lab mice, to put it nicely, exhibit a generally mild temperament. To put it less nicely, they appear collectively dull-witted, perhaps due to inbreeding.
Lately, Zheng Tan had often heard Mr. Jiao mention this in his genetics lectures on PowerPoint. So when he saw a cage full of lab mice, Zheng Tan felt this was indeed much like what Mr. Jiao had described; he observed no fear in the eyes of those mice—they might even have thought it was the Feeder, busily seeking food.
Mr. Jiao grabbed a mouse from the cage and placed it on the table, telling Zheng Tan, "Keep an eye on it, don't let it run off."
Zheng Tan looked at the mouse, which seemed oblivious to the fate it was about to face, and lifted a paw to hold down its tail. The mice, although restrained, didn't struggle much but displayed an intention to crawl forward.
See, that's the difference between wild and domesticated. If those outside caught their tail, they would either desperately try to escape or turn to bite.
Mr. Jiao put the cage containing the remaining four mice into an empty cardboard box to block their view of what was happening outside.
"I don't know how you cats catch or kill mice; I'm just telling you about some common methods we use."
As he spoke, Mr. Jiao took the mouse from under Zheng Tan's paws.
"Let me tell you, in domestic labs, the neck-breaking method is generally used. It is the least painful way for the mice to die. If done swiftly, they feel no pain at all, conforming to what foreigners would call animal welfare..."
Zheng Tan crouched nearby, watching quietly; he knew Mr. Jiao had entered his teaching mode again. Sometimes at home, after preparing his teaching PowerPoint, Mr. Jiao would rehearse by himself, with Zheng Tan as the listener. So, as soon as Zheng Tan heard Mr. Jiao saying, "Let me tell you," he knew he had slipped into his teaching mode again.
"Neck-breaking boils down to dislocating the neck vertebrae, severing the spinal cord from the medulla oblongata. One hand on the mouse's neck with a tool or directly, and the other hand on its tail, tug forcefully with both hands. That's one method. There's another method we often use, which you can try too. Watch..."
While explaining, Mr. Jiao grabbed the tail of the mouse with his left hand and pressed down on the neck of the mouse with his thumb and index finger of his right hand.
Then, there was no after.
Zheng Tan looked at the motionless mouse on the table, and then at Mr. Jiao's face, which seemed to say, "I believe in you," and twitched his ears.
"See, it's actually quite simple. Even if you've never caught mice before, it won't matter; you'll get the hang of it soon. I've seen the speed at which you hit Ah Huang, catching a mouse would definitely not be a problem."
The Ah Huang Mr. Jiao mentioned is a yellow tabby cat, also one of the mischievous friends Zheng Tan met after becoming a cat. Unlike "Sheriff," Ah Huang always did things that were both funny and annoying. Many times, Zheng Tan would just want to smack him, but Ah Huang hadn't been seen recently for some unknown reason.
Mr. Jiao then grabbed another mouse from the cage and let Zheng Tan try it for himself.
Zheng Tan killed the first mouse after pressing down three times before it finally stopped breathing.
When killing the second mouse, Zheng Tan applied too much force, but at least the mouse didn't suffer pain before it died. Zheng Tan felt increasingly grateful that he had turned into a cat and not a mouse, as each step down the food pyramid brought one closer to another kind of hell.
"Dislocating the neck is easy; the cervical vertebrae of the mice are very fragile. It's just your technique that needs refining," Mr. Jiao guided from the side. "Don't hesitate when you act. It's best to succeed on the first try, otherwise, it will be painful for the mouse. But remember, it's about severing the connection between the spinal and brain cords, not pulling the head off, which requires controlling the force. You have to break the neck but not pull off the head. Some of my previous students have inadvertently caused the mice's eyeballs to burst due to too much pressure."
Zheng Tan: "…"
Damn, that's horrific!
Zheng Tan looked at Mr. Jiao, who still maintained a calm expression while speaking, and suddenly felt that there seemed to be a cold gleam in Mr. Jiao's eyes.
Zheng Tan remembered discussing with a group of drinking buddies at a nightclub once, when someone said, "Actually, the most fearsome killers aren't those who look fierce, not those wielding large knives with tattoos and nose rings, nor those who constantly brag about their weapons to show how badass they are. It's those who look completely normal yet can easily take lives the next moment but still remain unflustered."
Thus, in a certain sense, some seasoned experimenters share a similar air to that of killers.
Experimenters in their element are truly fucking terrifying!
Zheng Tan wondered if perhaps Professor Jiao was the only person in the world who taught his own cat how to kill mice using the neck-breaking method?
By the third and fourth mice, Zheng Tan's technique had improved significantly, granting these two mice a more dignified death compared to the first two.
Out of the five mice, Mr. Jiao demonstrated with one, and Zheng Tan killed the remaining four.
After cleaning up the five dead mice, Mr. Jiao went back into the inner room and soon returned with a slightly larger cage, still containing five mice, only these were much larger.
"These are rats, lab rats are albino mutant brown rats. Use the same method as before, but you'll need a bit more force. The same principle applies: precision and control, strike successfully in one go. Do you need me to demonstrate?"
Zheng Tan shook his head.
"Good boy."
Zheng Tan: "…"
As Mr. Jiao had mentioned, the rats were a bit more challenging, but after practicing on five, Zheng Tan also became proficient.
"Do you need more practice?" Mr. Jiao asked.
Zheng Tan shook his head.
"Very well, let's stop our mouse-killing practice here. Look…"
Zheng Tan tugged his ear: "…" Here it goes again.
Even though the mouse killing was over, Mr. Jiao's teaching mode was evidently still ongoing.
"In our lab, apart from the common cervical dislocation method we use for killing small and large rats, we also have methods like decapitation, exsanguination, blunt force, anesthesia, lethal gas executions, and others. For example, for frogs, we use the spinal destruction method, which requires only one needle. Hmm… next week I'm teaching a zoology dissection class on bullfrogs, I'll bring one back to demonstrate for you then. Oh, and something you need to be particularly aware of, most of the methods for executing cats and dogs in the lab involve air embolism." After pausing, Mr. Jiao looked at Zheng Tan and asked, "Do you understand this?"
Zheng Tan shook his head, his muscles tensed and the fur on his back and tail were bristled, feeling as if the temperature around him had dropped.
"Simply put, this method involves injecting air into the veins."
Zheng Tan shivered. He understood that, even if his knowledge in this area wasn't strong, he knew what happens when air is injected into the veins.
"The air enters the blood circulation and travels to the lungs, blocking the pulmonary artery and causing severe shock or death. For instance, when you swim from a deep part to a diving spot, the change in pressure causes gases in the lungs to expand, which could lead to overexpansion if you don't expel the excess gases or if there's no time to do so. It's very dangerous—as some passengers on the Titanic died this way."
As Mr. Jiao spoke, he suddenly realized that mentioning the Titanic might not be helpful to a cat, so he shifted back to his main point, "So, you must be cautious in the future, keep away from dangerous objects, and be aware of how to save yourself."
After practicing mouse-killing techniques that evening, Zheng Tan felt more confident. Although he lamented the necessity of catching mice, as a cat, being recognized for catching mice was probably essential—even Ah Huang the dimwit could do it, and Zheng Tan believed he certainly could too.
When he returned to the East Family Courtyard, Zheng Tan saw a car parked in the open area, a familiar face with a military license plate.
It seemed that the plump guy had also returned from visiting relatives.
While Mr. Jiao went to park the car, Zheng Tan jumped onto the balcony on the first floor and peered inside.
On the desk by the window, there was a bag of instant noodles, and on it sat a slightly chubby tabby cat.