Last month when my son Diego was home from college I found him asleep one morning on the living room couch. He explained that he had abandoned his room because he woke in the middle of the night to a relentless tapping sound.

After an hour of trying to ignore the noise, he finally flipped on the light and—to his horror—saw that sitting on top of his lamp was a tiny, tapping rat.

My first reaction was to scream; my second was to laugh. I had no idea how a rat had gotten into his room, but the thought of it taunting Diego from the corner was beyond funny to me… especially since I’d been after him to clean his room for a month.

Rats (specifically non-pet rats) are generally disliked. They are associated with filth and disease and, over time, the word has taken on metaphorical meanings of ‘double-crosser,’ ‘hateful person,’ and ‘betray.’

In the early 1600s rats were known to scatter from sinking ships and falling houses. From this, the meaning of ‘traitor’ or ‘informant’ came about and expressions like “You dirty rat,” “I smell a rat” and “rat someone out” became commonplace. They emerged alongside unbecoming descriptors such as, ‘rat-fink,’ ‘mall-rat, ‘pack-rat,’ and ‘rats nest.’

And, if you grew up in my generation, you’ll remember the Schoolhouse Rock episode on interjections when little Billy loses the wheel on his go-cart and yells “Rats!”—a clear expression of anger.

Given my recent run in with a rat in the house, I was particularly curious this week to understand how such a foul little creature was able to snag the honorary position of first animal to represent the 12-year cycle of the Chinese zodiac. How is it that in Chinese astrology the rat is sometimes considered the king—more important than the ox, tiger, rabbit, dragon, snake, horse, sheep, monkey, rooster, dog and pig?

As it turns out the Chinese zodiac rat enjoys a distinguished reputation that the ordinary rat does not. Although there are a few explanations for the rat’s important position, most point to an ancient Taoist tale.

As the story goes, the Jade Emperor, ruler of heaven and earth, decided that each year of the Chinese zodiac should be represented by an animal. To determine the honorees, he held a race inviting all of the animals in the world to compete.

The emperor decreed that the first 12 to cross the heavenly river would earn the prestigious posts. The rat, who was good friends with the cat, was tasked with waking her in time for the starting gun. By some accounts the rat forgot and by others he deliberately let the cat snooze, forever edging her out of the Chinese zodiac (and forging a lifelong adversarial relationship).

The cat wasn’t the only one wronged. The rat was unable to complete the most challenging portion of the race alone—crossing the Heavenly river—so he asked the ox for a ride. The ox obliged, and when they neared their destination, the rat hopped off before the ox could lumber out of the water and became the first animal to cross the river.

Westerners might view this behavior as double crossing, but Easterners have a different take on the story. People who are associated with the rat are seen as intelligent and willing to do anything to get what they want. The zodiac rat is instinctive and shrewd—he symbolizes fertility, positivity, wit, flexibility and agility and is associated with wealth and surplus.

As for real rats, there has been much research which delves into their personalities. In one such study, it was determined that rats communicate verbally with each other in noises that are above our range of hearing. New York subway rats were recorded and the pitch was lowered so that researchers could detect social patterns.

They were able to determine that rats change their speaking patterns when socializing, courting, parenting and laughing. Yes, laughing! The most shocking discovery was the realization that rats laugh (and apparently can be tickled).

Indeed, there is an old Chinese proverb that states “When men discuss the things which are to be, the rats laugh in the rafters,” which brings me back to Diego. Is it possible that the little rat was laughing in the corner at the college kid who refused to clean his room? Perhaps the happy rat will bring us luck?

For good measure, I did send Diego the following text when he returned to college, which happened to fall on the first day of Chinese New Year: “Happy Year of the Rat! For your gracious deed of hosting the clever king in your bedroom, I predict that the rat will repay you with wealth, prosperity and a positive attitude in 2020.”

I’m sure it made him smile, but like the rat, I got a very good laugh out of it.