Pest control: Should we even ask if there is an ethical way to kill rats?

Reasons for controlling the urban rat population are abundant: The animals can spread diseases to humans, destroy property and damage native ecosystems. But rats are also cognitively advanced social animals, and questions about how to effectively control them can raise tricky ethical questions. Glue traps will leave rats starving, for days, before dying. Poison leads to a slow, painful death and can endanger other wildlife. Standard wooden snap traps often catch limbs or tails, forcing rats to gnaw them off in desperation. Live-catch traps are difficult to implement, and when many rats are stuck in the same place together without food, they sometimes eat one another.

Even if rats are extracted from an urban environment, what do you do with them? Release them into the woods, where they can damage existing ecosystems? Keep them as pets? Rats are reviled but resilient, dangerous but inculpable. “Right away, you end up in a very uncomfortable position,” said Robert Corrigan, a New York City rodentologist who has studied urban rats for decades. “There’s no way to get out.”

There are more than 4,400 mousetrap patents in the United States, but it is difficult to find designs specifically for catching rats — most are just bigger mousetraps. Rat infestations are also often more of an industrial undertaking than mouse infestations are, less of a do-it-yourself project and more of a job for professional exterminators, who are better at reusing traps. Partly because of this, Woodstream, the country’s largest rat and mousetrap manufacturer, sells some 60 million mousetraps a year and nine million rat traps, according to Miguel Nistal, the company’s president and chief executive. Most of these are the classic wooden spring-loaded snap trap, which Woodstream sells under the brand name Victor.

Nistal said that the main complaint he gets about his rat traps is simply that they don’t kill rats. Mice are relatively uncomplicated pests; they go for whatever food source is available and, because they’re small, are easy to dispatch. But Nistal said that, according to his company’s research, only about 65 percent of the rats that trigger snap traps die. They will wriggle free or outsmart the trap, swiping the bait out safely. Rats are also wary of new things, like traps. “When you and I are gone, and there’s nothing else on earth, there will be roaches and rats,” Nistal said. Shawn Woods, a YouTuber who reviews mouse and rat traps, said that he often has to leave his rat traps out for a couple of days without setting them so the animals feel safe grabbing the food. Woods tests a trap every week and has a collection of thousands of rodent traps at his home in Oregon. He began making review videos about six years ago, when his channel had only a handful of subscribers and was focused on primitive survival skills. Then, a video demonstrating an ancient deadfall trap received over a million views.

Since then, Woods has become an influencer in the trapping world, with over 1.7 million subscribers to his channel. New products that he gives positive reviews often sell out on Amazon, and he has met with management at trap manufacturing and design companies, including Woodstream, to share his expertise.