In Journey to the West, what exactly is the “sleepy bug” used by Sun Wukong?

As a classic literary work, many magic weapons in Journey to the West have always been talked about. The sleepy bug is one of them. On the journey to obtain scriptures, Sun Wukong often used this small bug to make monsters or others sleepy and easy for him to act secretly. Sometimes these small bugs were transformed by Sun Wukong plucking hairs, and sometimes they were won by guessing numbers with gods in the past. With Sun Wukong's clever use, the sleepy bug helped a lot in the journey to obtain scriptures. So, who exactly is this magical little bug?

The earliest record of sleepy bugs appeared in Buddhist scriptures. The "Fayuan Zhulin" (completed in 668) compiled by the Tang Dynasty monk Dao Shi mentioned the "sleepy bug". It is tiny and dust-like, and often lives in various parts of the human body, such as the bone marrow, muscles, skull, and cheeks. When it flows to the human heart, the heart rhythm will be disturbed. When the bug sleeps, the person will sleep. If the sleepy bug is extremely tired during the day, the person will also sleep during the day.

As Buddhist stories became more popular, similar things also appeared in literary works. In the Bianwen story "Eight Phases of Transformation" discovered in the Dunhuang Caves, there is a saying that "the gods communicated with each other (taught) a sleepy god to come down to the world, making all the people drowsy." It may be one of the inspirations for the design of this lively little insect in "Journey to the West".

To explore what species the sleepyhead is, we can first look at the habits of the sleepyhead in "Journey to the West".

In Chapter 5, when stealing wine at the Peach Festival, Sun Wukong flicked the sleepy bug onto a person's face, and the target "became limp, lowered his head, closed his eyebrows and eyes" and "took a nap". In Chapter 25, Sun Wukong used the same method to deal with the Taoist boy at Wuzhuang Temple. In the later period of the journey to the West, the use of the sleepy bug was further explained. In Chapter 71, in order to deceive the golden-haired lion who abducted the Queen of the Golden Palace, Sun Wukong put the sleepy bug on the face of Chunjiao (actually a jade-faced fox spirit), the Queen's personal maid. The author further explained: "It turns out that when the sleepy bug gets on a person's face, it crawls into the nostrils, and once it crawls into the nostrils, the person will fall asleep."

According to the author's description, we can see that the sleepy beetle has two characteristics: First, the sleepy beetle probably does not have wings that can fly. Because when Sun Wukong ejects and throws it, if the sleepy beetle can fly, it may not be able to hit the target accurately. Second, the sleepy beetle can crawl into a person's nostrils by itself, and it is likely to be a burrowing creature.

We can find the prototype of the sleepy bug in ancient books. Soon after the novel "Journey to the West" was published, someone discussed its origin in a review. This enthusiastic reader was named Huang Bingshi, who was active during the Wanli and Tianqi years of the Ming Dynasty. In his essay collection "Occasionally Obtained Blue Pearls", he discussed the origins of ginseng fruit and sleepy bugs. Regarding sleepy bugs, Huang Bingshi said: "There are also sleepy bugs. The sea sandworms live in the cracks of rocks. They like to sleep and are called sleepy bugs. They can be used as poison to shoot people and animals."

The earliest record of the term "Sandworm" can be found in the "Supplement to Compendium of Materia Medica" written by Chen Cangqi, a medical scientist in the early Tang Dynasty. The book says that this small insect "can be found everywhere. It grows in sand and stones, with spiral holes. It is as big as a soybean, has thorns on its back, and can walk backwards", so it is also called "backwards walking dog". Chen Cangqi also said that it "likes to sleep, so it is also called a sleeping insect". Later medical books followed these statements.

What are the effects of this little insect mentioned in the "Supplement to Compendium of Materia Medica"? Chen Cangqi did not say what medicine it could be used to make, but only said that it was poisonous, "Put it in the pillow when it is fresh, it can make couples love each other. It can kill birds and beasts when it is used together with arrows." This use was also developed in later records. The Song Dynasty collection of notes and novels "Taiping Guangji" quoted the record in "Bei Meng Suo Yan" written by the Five Dynasties scholar Sun Guangxian, saying that a medicine seller in Chengdu sold "aphrodisiac" to young people in the city at a high price. Sun took it to see, and then he realized that it was a sand squeezer (called sand prisoner by the Shu people). The Ming Dynasty playwright Tang Xianzu also said in "Wuling Chunmeng" that "In the Ming Dynasty, I stood in front of Bei Cuizhou and picked up a sand squeezer and put it in my pillow", which is also a reflection of this folk remedy.

People in the Ming Dynasty became more interested in natural history, and the description of the sand shovel became more detailed. Tan Zhenmo wrote the earliest Chinese entomology book "Tan Zi Diao Chong". The book said that the sand shovel was also called "monk insect", and there were two forms: one "black shell with red spots like lacquer, walking between tables, with a round body like a bald head, as big as half a red bean, with wings in the shell and eight legs under the abdomen"; the other "shell is ochre yellow, with black spots on it, in pairs, shaped like a melon seed, with two whiskers and six legs".

The sand shovel is actually the larva of the antfly, also known as the antlion. It is generally less than 1 cm long, with a sturdy spindle-shaped body, a plump abdomen, and a pair of huge sickle-shaped mandibles on its head. Antlions are good at digging traps to prey on other insects. After they choose a place to dig a pit, they crawl backwards, use their abdomen as a plow to dig the soil, use their front legs to move the soil particles to their heads, and then pull and throw the soil out of the small pit, so that it can dig in a spiral toward the center until a steep sand slope funnel is formed. Then the antlion opens its jaws at the bottom of the funnel and waits patiently for an opportunity to move, looking as if it is asleep. When ants and other small insects pass by the funnel, they can easily slide down and become the prey of the antlion. The antlion injects toxins into the prey, absorbs its body fluids, and then throws out the debris.

Antlions are also well-known in Western entomology. The book Physiologist in the Roman period regarded them as a hybrid of an ant and a lion, saying that the ant half only eats husks, while the lion half only eats meat. This dual nature caused its offspring to be at a loss and starve to death. The description of antlions is also a famous article in the 19th century naturalist Fabre's "The Insect Book".

It can be seen that ancient Chinese herbal medicine and entomology works give relatively accurate descriptions of the antlion's living environment, body shape, and habits of walking backwards, digging holes, and releasing poison. Journey to the West emphasizes its superficial characteristic of "sleepiness" as a skilled hunter in nature. The author then uses his rich imagination to integrate it into the story of the journey almost seamlessly. From then on, the sleepyheaded bug became famous and gradually overshadowed the sand scraper that served as the prototype.