Our beautiful neighborhood has much to recommend it. Abundant green space. Wide boulevards. An endless array of restaurants. And we’re not the only ones who have noticed. In addition to the explosion of salmon-colored shorts and upspeak polluting our idyllic streets, another, less-visible infestation has taken hold.
Rats. Specifically, the Norway, or brown rat (Rattus norvegicus).
At least the Chads and Trixies don’t typically jump out of dumpsters and scare the living daylights out of unsuspecting residents, which is more than I can say for our rodent neighbors. It’s rare that a Logan Squareite hasn’t had at least a couple of close encounters with rats.
I had one run over my foot coming out of the train station (blessedly, while wearing close-toed shoes). And a squabbling pair of them rolled end-over-end, cartoon style, right in front of me as I was walking home one night. Countless others have tested my cardiac resilience by catapulting out of trash cans and rocketing out of recycling bins at alarming speeds. One learns to listen very closely for rustling when selecting a waste receptacle in Logan.
We’re not alone in facing the buck-toothed horde. Chicago was named the rat capital of the United States by pest control company Orkin for the third year running in 2017. So, Logan isn’t an anomaly. We do, however, seem to hold a special appeal for vermin even within our rat-friendly city. In 2016, Logan lagged behind only West Town in the number of rat complaints made to 311, which numbered nearly 47,000 for the whole city.
A Veritable Smorgasbord
So, why us? There are plenty of other neighborhoods to choose from. We’re not the only ones with prime rat real estate and dumpsters that runneth over with food scraps.
For answers, I turned to Dr. Lawrence Heaney, curator of mammals and co-chair of the pest committee at the Field Museum.
Heaney shared the concerns of residents but notes the difficulty of accurately assessing the true extent of the rat invasion.
“There is no question that the rat population in the Chicago area is very high,” Heaney said. “It is difficult to judge which city is the very worst because the evidence is limited—but it is very clear that we have a serious problem.”
He goes on to explain that we should take the city data on the neighborhood-level populations with a grain of salt. “Owners are more likely to report problems than renters, and non-resident landlords may report problems less often than resident landlords. So, tallies of complaints should be taken only as a rough indicator of problems.”
So, it’s entirely possible that we’re not, in fact, the second rattiest neighborhood in the city. Perhaps we just have the second highest population of complainers.
Superlatives aside, we’ve certainly got a problem. And, as Heaney noted, we’ve got no one to blame but ourselves.
”The single biggest cause of high rat populations is the abundance of food available to them,” he said. “So, the only way to effectively reduce or eliminate rat populations is to remove their food. Currently, most cities in the U.S. present rats with a constant cafeteria.”
When you present a fecund species like the brown rat with a buffet, they will breed like, well, rats. “These rats—which are not native to North America, they came with people from Europe— have an exceptionally high rate of reproduction,” Heaney asserted. “An adult female can have at least four and sometimes as many as six litters in a year, and each litter has four to eight babies. The babies begin reproducing when they are about four months old—so just a few rats can quickly turn into hundreds. The more food available, the more babies they make.”
What, then, do we do about the devious creatures?
”The best way—and one that is entirely natural—is to make certain that the rats do not have access to food. In the city, that means hav[ing] containers for trash that are tightly sealed, with no holes, and enough containers that there is always enough space for the trash,” Heaney said. “If you see bags of trash piled on top of or beside trash containers for a couple of days prior to weekly trash pick-up, or a container that is open or has holes that have been chewed by the rats, you are seeing a rat cafeteria.”
Even the tidiest alleys, though, are no match for the wits of these surprisingly intelligent mammals, which have demonstrated a remarkable aptitude for learning and self-awareness in laboratory settings. In the wilds of Logan, they invade all but the most securely lidded trash containers. Plastic is hardly an obstacle, as evidenced by the numerous blue recycling bins perforated by rat-sized holes.
The city—and private contractors—trap and poison them. These methods have limited utility, because, as Heaney explained, when they see another rat die in a trap, they never go near another trap.
“If they see a rat die after eating something [for example, poison bait], they never go near that bait. So, traps and poison mostly kill babies that are quickly replaced,” he said.
Other Solutions to the Rat Problem?
Recent initiatives to place dry ice in rat burrows in order to suffocate them with sublimated carbon dioxide were quashed by the EPA, which requires that pesticides go through an approval process.
The Tree House Humane Society’s Cats at Work program introduces feral cats to rat-infested neighborhoods in the hopes that the felines will hunt and repel the rodents. While supporters characterize the initiative as more eco-friendly than poisons, which can also affect other wildlife, some are concerned that the cats will also eat birds. A 2013 study showed that free-ranging cats kill up to 4 billion wild birds a year in the United States. And Heaney is skeptical of their efficacy in controlling rats.
“Studies of feral cats show that they kill only small numbers of baby rats, and almost never the adults,” he said.
Coyotes are more effective—and the stealthy canines are around. But there just aren’t enough of them in Chicago to make a significant dent in our rat empire. There are perhaps 2,000 of them here—no match for the estimated several million rats.
So, they’re not going anywhere anytime soon. Rats have been living alongside humans for thousands of years. Initially more common in the West was the black, or roof, rat (Rattus rattus), the carrier of the bubonic plague or Black Death. That species is now rare or absent in Illinois. The brown rat is thought to have arrived in Europe from Asia about 1,800 years ago and from there traveled to our shores. Its adaptable nature and rapid reproduction rate have allowed it to spread across the continent.
Besides keeping our trash secure and eliminating their food sources, there’s little we can ultimately do to stem the tide. Though rats do pose a disease threat—a Leptospirosis outbreak in dogs in 2016 was of particular concern—and can damage property and electrical wires by chewing, you really have very little to worry about from our furry fellow residents when you encounter them in person. Healthy rats are usually quite wary of humans and are unlikely to bite unless cornered. And, as several studies have shown, rats are capable of empathy for each other.
Perhaps, in that spirit, we might show them a bit of empathy ourselves.
Illustration by Shanti Rogers.