A rat hole in McPherson Square proves a safe haven for a young rodent. (Michael S. Williamson/The Washington Post)
Columnist

The man in charge of rat control in the nation’s capital has spent three decades studying the habits of rodents.

He knows they enjoy eating chicken.

He knows that as their families grow, some members get pushed to find new homes.

He knows that if a single whisker on a mouse’s face touches a glue strip, that mouse will learn to forever avoid that type of trap.

“They are geniuses,” said Gerard Brown, program manager of the D.C. Department of Health’s rodent control division. “You don’t survive that long if you’re dumb.”

Brown could have said “smart” or “shrewd,” but neither of those words would have felt as accurate.


Gerard Brown, who heads the city’s rodent control program, knows they are “geniuses.” (Sarah L. Voisin/The Washington Post)

I know this not because I have spent days with him searching for rat holes in the city or because I have dedicated countless hours to sifting through scientific research.

Those tasks would have actually been preferable to the way I learned about rodent intelligence: an experiment in my living room.

To some people, rodents are simply disgusting. To others, they are fascinating. I am among those who find my irrational fears plucked at just the thought of their claws.

Because of that, I would rather not tell you about the experiment. I would rather forget it completely. But I’m sharing it because I think it’s important that we know what we’re up against at a time when rodents are literally stepping out of the shadows (and trash cans and drainage ditches) in Washington, D.C.

In recent years, the District has received between 2,000 and 3,000 rat complaints, Brown said. Last year, more than 5,000 complaints came in, and if calls about mice were also counted, Brown said, that number would have been much higher.

In other words, it’s bad, people. So bad that a mother mallard that had set up a nest outside of the U.S. Department of the Interior, and had become known as #DOIduck, was chased away by a hungry rat earlier this month, as reported by my colleague Marissa Lang. The long-tailed invader then feasted on eight of her eggs and left her sole surviving offspring to hatch with no mother in sight.

Some might have judged that mother duck for her abandonment.

I sympathized with her.

The experiment in my living room began in a much less dramatic way: tiny droppings that told my husband and me we no longer were alone with our two small children in our townhouse. My first instinct was to scoop up the kids, rent a hotel and sell our house. When practicality prevailed, I cowered on a higher floor that I was confident hadn’t yet been breached.

The mice had to go. On this, my husband and I agreed. Where we disagreed was on what “go” meant.

I meant go toward a trap-induced death that guaranteed they would never return.

He wanted them to go back outside, alive.

We decided to compromise: He had one week to try to catch them with humane traps.

We bought three that resembled houses. The walls were a translucent green that made me wonder whether they were designed to allow us to see in or the mice to see out. We filled each with rodent-enticing snacks and placed them strategically across the room, which connected to our kitchen.

Then we waited.

One night passed. Then two. Then five.

After seven evenings without success, and my growing paranoia that I was going to wake up with a mouse nestled on my pillow, it was finally my turn to try the death traps. Unlike the inviting houses, these had opaque black walls with an undeniable purpose: to hide the gruesome results of their triumph.

I filled them with the same snacks we had been using and placed one near each humane house.

Success, of sorts, came the next morning.

We found one of the mice in a trap. But it was neither hidden nor dead. There, from the inside of a translucent green house, it looked at us, and we looked at it. Then our children saw it and excitedly asked whether we could keep it. We explained that it preferred to live outside, far from any people, and that’s where my husband released it.

We figured the live catch was a fluke. There was no way, we thought, that mouse had consciously considered its options and had chosen eviction over death.

The next morning, we caught the second mouse.

It was chubbier and fluffier than the other one. I know this because I saw it, munching comfortably away inside its new home. It, too, had chosen life and a trip outdoors.

I told this to Brown when we spoke about the city’s rodent problem, and he wasn’t surprised by their intelligent response. He knows how strong their will is to survive. He knows rats can climb straight up a brick wall and mice can slip through a space a quarter-inch wide.

He also knows not all humans are eager to see rodents killed. Even the rats have sympathizers who call his division and ask whether there are more humane ways to control the population.

Currently, the city places dry ice in rat burrows to suffocate the occupant and uses a lethal powder that is shot into the rat holes and attaches to the animal’s fur. But come October, Brown said, a nearly $1 million budget increase toward rodent control will also allow the city to implement a program that has been used in New York and doesn’t end in death. The rats will be fed a sweet liquid that leaves them sterile.

Brown said his division will also continue to focus on a crucial component to combating the problem: public education. Residents and business owners, he said, need to follow proper sanitation and call 311 when they observe a rat hole.

As for household mice, apparently even the head of the rodent control program, who jokes that his wife cleans so well, “I think she’s going to wipe the paint off,” has to combat the occasional one in his house.

His solution, he said, doesn’t let them choose how they want to leave.

“I use snap traps,” he said.