Inside a square glass box, a snail was crawling slowly. It was an Amber Snail, a mollusc found commonly in china. Its preferred habitat are the dark and wet places like the drains. It also prefers heavy moisture but it can resist moderate heat and cold. It can also float on the surface of water. It feeds on decomposed material and young sprouts of plants like lichen, moss, mushrooms and so on. The shell of an amber snail can range from many different sizes but they are normally oval in shape. They have 3 to 4 whorls and they can be from 5 to 15 millimetres tall and 3 to 8 millimetres wide. Their shell is thin and the surface is usually yellow or brown in color. Their body is translucent or half-translucent.

However, in this case the snail inside the glass box had two particularly swollen antennae. Compared to a normal amber snail, this snail was quite different. Inside its translucent body, one could see the presence of alien objects. They were not the snails internal organs. Suddenly, the snail started to crawl with a speed not common for a mollusc. Its swollen antennae were like two drills. The bands of colors spun and shimmered.

Students, this here is a snail infected by a parasite. The color and lights that you see are actually a large amount of parasite wiggling inside its body. In the biology class, the teacher explained carefully. The monitor showed a slow-motion video of the snail inside the box with 10 times amplification. It was still the same amber snail but the students could see the horrifying details. The thing was not glowing naturally. The snails body was stuffed with parasites. They wiggled and squeezed against each other.

These are Leucochloridium paradoxum, or the green-banded broodsac. It is these parasites that cause the genetic mutation to the snails body. They also control the snails mind. The video changed and it now showed an image of the parasite under the microscope. It looked like a giant worm. Some of the students frowned while others looked on with interest.

First, the snail ingested the parasites eggs. The middle-aged lecture continued, And that was how the parasite entered the hosts body. Then the eggs will travel to the snails digestive system to develop into their next stage, the sporocyst. At this moment, the snail appears perfectly normal, perhaps even itself has no idea there are parasites in its body. The nutrients that it consumes from food are constantly stolen by the parasites. Then again, we arent snails so we cannot be sure about this. We cannot tell how they feel exactly.

A small laughter echoed in the classroom but it soon died down. The simulated video on screen showcased the growth of the parasite. The sporocyst grows into long tubes to form swollen broodsacs filled with hundreds of cercariae. These broodsacs invades the snails body, specifically its antennae, causing them to transform into swollen, pulsating, colorful displays. The growth expanded the antennae in size so much that the snail could not retract them anymore and the bright antennae could only be dangled outside its shell. Watching these images, the students felt sorry for this poor snail.

Once the broodsacs enter the snails antennae, they will gain the ability to control their host. Amber snails are nocturnal creatures but after being taken control, they will become active around daytime and appear at places where sunlight is plenty. Furthermore, they will now move 3 times faster than usual. In a way, the parasite has helped the snail broken through their biological limitation. The teacher gestured at the mutated snail inside the box. Its antennae glowed like disco sticks. Currently no research knows how the broodsacs manage to take control over its host but I am sure some of you will figure out the mechanism in the future. Despite its size, this parasite is incredibly clever. They transform the snails antennae into a swollen display of colors, imitating the appearance of a caterpillar. The parasite deprives their hosts of its fear and controls them to move under the sun. They will also control the snails to move to higher elevation to make themselves as pronounced as possible. Why? This is for the birds to see them. Once the birds see the shiny object shaped like a worm, theyd swoop down to swallow it. However, in this case, the caterpillar is actually the snails antennae filled with broodsacs.

The teacher paused and wrote down the following on the blackboard. He stressed, Aggressive mimicry, this is how the broodsacs benefits from this phenomenon.

Aggressive mimicry is a biological concept, to put it simply, an organism uses promises of mating or food to lure its prey into its trap. For example, the pitcher plant would mimic a flower to attract bugs. Consumption, survival, mating, this is natures brilliance.

The snail is the primary host. The teacher continued to write on the blackboard. The birds are the secondary hosts. After the broodsacs are ingested by the birds, they will start to reproduce. Then their eggs will be ejected out alongside the birds faecal matter. The faecal matter would be food for other snails and thus begins another cycle.

The students felt chilled and revolted. The broodsacs turned the innocent snails into fake food to prey on the birds. These parasites were small but they could engineer such malicious and eerie tactics. They could even discern the difference between night and day, and difference in elevation. They knew how to control their hosts to make them as conspicuous as possible. Be it brilliance or instinct, this was scarily surprising.

Sir, then can the broodsacs control the birds? A male student asked.

There is no evidence so far that supports that.

Then can it enter the human body?

These are not mind-controlling parasites from video games. The teacher chuckled. Our human body is far more complicated than that of a snail and bird. We also have a strong immune system. However, we do have other parasites to deal with, for example, the tapeworm. And, I know what youre going to ask next. No, there are currently no parasites that can control human mind and action. Well, perhaps there is one. The name is money. The teacher added, Latin name Aes.

The students chuckled. Indeed humans are not snails, they should not be taken control by parasites so easily.

At the same time, inside the glass box, the snail continued to crawl without a moments respite.

The call was connected.

Hello, is this Wang Jia Ers mother? I am Lee Yuhans mother. Yes, our sons stay at the same hostel.

Oh, yes. How can I help you, Mrs. Lee?

Its like this. Yuhan told us yesterday night that he and a few friends would be spending a night over at your house. I called him this morning and there was no answer. Its getting to be noon soon and still theres no answer. I have Jia Er and his friends numbers too. I call all of them but none of them is picking up

Is that so Mrs. Lee, Jia Ers father and myself have been overseas for the past few days. But dont you worry, the youngsters must be up late for a party. Its a weekend today, so theyre probably still in bed.

I thought so too but somethings strange None of them has posted anything on their social media since yesterday night. If they had a party, wouldnt they have plenty of pictures to share?

Hmm how about this? Ill call my neighbourhood watch to send someone over to check on the house. Perhaps theyre just drunk.

Okay. Mrs. Wang, thank you so much and sorry for the disturbance.

Its no problem, this is Jia Ers doing after all.

The call ended. Half an hour later, the call was returned.

Hello, Mrs. Lee? The guard went to check earlier. There was no one home and my house garage door was left open. I looked at the picture sent over and the MPV is missing. I had the guard check the neighbourhood camera. The car was driven out yesterday night. Jia Er was behind the wheel and Yuhan and the rest were also inside the vehicle

What Jia Er knows how to drive? But where were they going?

Im not sure but Mrs. Lee, Im sure its fine. They are just being young, we shant panic.

This has gone far enough, we should call the police.

Wait, Mrs. Lee, we dont need to make this such a big deal just yet Mrs. Lee, dont think Im just covering for my son. What if every single one of them is involved in something illegal? After all, we dont know anything. If, and Im just speculating here, what if they have illegal substances like pills or cannabis on them? If we call the police, their future will be ruined!

What? You, this But shouldnt their safety be our primary focus? Furthermore, my Yuhan will never touch drugs.

I was just making a speculation. Wait, Mrs. Lee, quick, log onto your social media! My Jia Er just updated his status. See if your Yuhan has done the same.

Let me check. Oh, yes, he did! So he has his phone with him, then why didnt he pick up? He didnt even think about sending a message back to report his safety. These kids they really want to scare the hell out of us. But then what is the meaning of this update I witnessed God, I am his incarnation in the human world.

Jia Er uploaded the same status. Probably they went to their idols concert?

Probably. This kid Mrs. Wang, Im not going to trouble you anymore. Ill call Yuhan again. When he comes home, therell be a beating for him.

They are just being youths, a little lecture should suffice, but youre right, Ill have to deal with Jia Er when I return home too.