Freakonomics Radio: "Why Does Everyone Hate Rats? (Update)"

Host: Stephen J. Dubner
Originally aired: April 22, 2026

Overview

With springtime in New York City and rats emerging in force, Stephen Dubner revisits and updates one of Freakonomics Radio’s most popular episodes: an exploration of humans’ complex relationship with rats. The episode investigates the roots of rat hatred, their actual impact on public health, the social, economic, and psychological reasons behind our collective aversion, and surprising cultural differences in their reputation. With fresh data and new perspectives, Dubner and a lively cast of guests probe the surprising, often misunderstood realities of urban life’s most reviled animal.

Key Discussion Points and Insights

1. Rats and Urban Life: The New York City Context

• Springtime Means Rats: Warmer weather in NYC correlates with increased rat activity ([01:03]).
• Government Action: NYC created a new position—a so-called “Rat Czar” tasked with rodent mitigation.
• Eric Adams' Crusade: Former Mayor Eric Adams positioned himself as fervently anti-rat, highlighting the trauma many New Yorkers associate with rats ([02:05]).
  • “Fighting crime, fighting inequality, fighting rats. Public enemy number one, many of you don’t know are rats. If you’re not scared of rats, you are really my hero.” — Eric Adams ([02:46])

Kathy Karate: The “Rat Czar” Experience

• Background: Kathy Karate, NYC’s first Rat Czar, describes her unconventional path—from childhood activism (petitions to clear out rat harborage) to citywide leadership ([06:01]-[07:03]).
• Sanitation is Key: “The key to pest management, any pest management, first and foremost, is sanitation.” — Kathy Karate ([07:33])
• Challenges in Counting Rats: Estimates of NYC’s rat population vary dramatically; there’s no official census ([08:11]).
• Commensal Species: Rats thrive where humans do, feeding off our waste and infrastructure ([09:05]).

2. Understanding Rats: Brains, Behaviors, and Adaptation

• Intelligence and Adaptability

  • Rats are clever, exhibiting adaptability—testing new food for safety and showing signs of empathy and laughter ([10:07]-[10:29]).
  • “In terms of adaptability to survive, there’s few species greater. … No one except humans exploits an urban space better.” — Kathy Karate ([10:26])

• Species and History:

  • Two main types: the brown rat (Rattus norvegicus) and black rat (Rattus rattus).
  • “Because everybody who hates rats wants to name them after somebody they don’t like.” — Bethany Brookshire on the naming of the “Norway rat” ([11:36])

3. Rats, Disease, and the Truth About the Black Death

Historical Villainy

• Changing Reputation: Rats weren’t always deemed “disgusting”—their image as disease carriers arose in the 18th-19th centuries ([12:05]).
• Pandemics and Plague:
  • Bubonic plague is a disease of rats and fleas that occasionally jumps to humans with catastrophic effects ([14:08]).
  • “The plague is technically not a disease of humans. It is a disease of rats and fleas that happens to spill over…” — Bethany Brookshire ([14:20])
  • Plague still exists globally but is exceptionally rare in the modern U.S.

Revisiting Blame: Did Rats Cause the Black Death?

• Scientific Debate: Nils Christian Stenseth and colleagues suggest that human ectoparasites (lice, fleas) may have been the primary disease vectors, not rats ([19:41]-[21:10]).

  • “It became very clear that rat could not have played a major role in the spread of plague in Europe.” — Nils Christian Stenseth ([21:10])

• Rate of Transmission: The traditional spread via rat-flea-human is too slow to explain historical patterns; human-to-human transmission via body lice and fleas is more plausible ([21:21]).

Modern Public Health Impact

• Leptospirosis and Other Threats:

  • Leptospirosis (via rat urine) is a real but minor threat (24 NYC cases in 2023; pop. >8 million) ([26:10]).
  • Rats harbor other pathogens, and proximity does pose theoretical risks ([26:38]).

  “There’s also a public health risk. Leptospirosis is one of the more famous illnesses associated with rats… but it’s certainly not the highest public health risk we have across our city or the globe.” — Kathy Karate ([26:10], [26:25])

4. The Psychology and Sociology of Rat Hatred

What Makes a Pest?

• Subjective Definitions:
  • 'Pest' is a label we assign to animals who are, as Bethany Brookshire puts it, “not where we want them to be” ([30:04]).
  • “The fact that we’re so quick to blame the rat says a lot about us. The thing that causes most diseases in humans, like communicable diseases, is other humans.” — Bethany Brookshire ([30:39], [31:15])

Cultural Differences

• Different Attitudes:
  • In India, the Karni Mata temple reveres and feeds 25,000 sacred rats—believed to be reincarnated ancestors ([35:34]).
  • In contrast, Western urban cultures focus on disgust, psychological stress, and a sense of violation when rats are present ([35:00]).

Historical Parallels: Other “Villainous” Animals

• Pigeons’ Rise and Fall:
  • Pigeons were once valued for food, messaging, and fertilizer. Now, they’re pejoratively “rats with wings” ([33:39]-[34:20]).
  • “We used to have such a use for them, and now we don’t. And we can’t fathom why they won’t go away. It’s so sad.” — Bethany Brookshire ([34:28])

5. Economics, Cities, and Rats

Negative Externalities and Adaptation

• Costs and Consequences: Rats damage property and infrastructure, which imposes public and private costs ([25:16]).
• Cities as Ecosystems:
  • “When cities are at their best, they do enable people who are outsiders to thrive. It’s hard to imagine more of an outsider than a rat.” — Ed Glazer ([23:17])
  • Rats and disease “tend not to be density multipliers about the good things about cities... but they do seem to carry the negative stuff…” ([24:50])

Should We “Exonerate” the Rat?

• Sympathy vs. Eradication:

  • The fear and disgust we feel may be outdated; disease risk is low in modern contexts.
  • “I think some control, but not making a fetish out of complete eradication.” — Ed Glazer ([40:50])

  “It’s hard not to think that rats have gotten something of a bad rap. … They’re in some sense our natural city partners.” — Ed Glazer ([41:16])

Notable Quotes & Memorable Moments (with Timestamps)

• Eric Adams’ personal crusade:
  “If you walk down the block and a rat runs across your foot, you never forget it. Every time you walk down that block, you relive that.” — Eric Adams, ([02:16])

• On sanitation and pest management:
  “The key to pest management, any pest management, first and foremost, is sanitation.” — Kathy Karate, ([07:33])

• Rats as commensals:
  “They are thriving and existing because of the plate we’ve set for them in our urban spaces.” — Kathy Karate, ([09:05])

• Historical bias in the Norway rat’s naming:
  “Because everybody who hates rats wants to name them after somebody they don’t like.” — Bethany Brookshire, ([11:36])

• Reframing the Black Death:
  “It became very clear that rat could not have played a major role in the spread of plague in Europe.” — Nils Christian Stenseth, ([21:10])

• On our hatred of rats:
  “We really hate them. We hate their success because their success feels like our failure.” — Bethany Brookshire, ([04:24]; [38:03])

• Animals as pests—only in the eye of the beholder:
  “The animals are just being animals. They’re about us. They’re about where we think animals belong and what we think those animals should be doing.” — Bethany Brookshire, ([30:04])

Important Timestamps for Key Segments

• [01:03] Introduction—Springtime rats in NYC and the new "Rat Czar"
• [02:05 – 02:57] Eric Adams on his hatred of rats and civic trauma
• [06:01 – 07:03] Kathy Karate’s early activism and start in rat mitigation
• [09:05 – 10:26] Rats as commensal species: their relationship to humans
• [12:05 – 14:08] Bethany Brookshire on rat reputation, plague, and disease history
• [19:41 – 21:10] Nils Stenseth’s research exonerating rats from the Black Death
• [23:17 – 25:16] Ed Glazer discusses rats as urban “outsiders” and economic actors
• [30:04 – 31:15] Bethany Brookshire on the subjectivity of “pests” and blame
• [35:34 – 37:24] The sacred rats of Karni Mata temple in India
• [40:50 – 42:20] Ed Glazer on sensible rat policies, sympathy for rats
• [42:52 – 43:36] Recent rat mitigation successes and ongoing city plans

Conclusion

The episode deftly shifts the lens from rat eradication campaigns and public health fears to a deeper examination of human psychology, cultural differences, and the unintended consequences of our urban coexistence with a highly successful animal. Listeners are encouraged to question whether our hostile attitudes toward rats are truly justified today—and to consider what our relationship with pests might say about us.

Memorable moment:
“It’s hard not to think that rats have gotten something of a bad rap... They’re in some sense our natural city partners.” — Ed Glazer ([41:16])

Final note:
If you enjoyed this conversation, the episode is part one of a three-part series about rats—find more at freakonomics.com/rats.