Unexplainable Podcast: "Real-life zombies"

Host: Bert Pinkerton (Vox)
Guest: Mindy Weisberger, science writer
Date: October 1, 2025
Theme: Exploring the extraordinary natural phenomena of zombification in insects (“zombie bugs”), how these real-life zombifiers manipulate their hosts, and what science is uncovering about these strange relationships and their broader implications.

Episode Overview

The Unexplainable team dives into the gruesome, fascinating world of "zombie" bugs—living organisms whose behaviors are hijacked by other forms of life (such as fungi, viruses, and worms). Science writer Mindy Weisberger joins host Bert Pinkerton to discuss her book, Rise of the Zombie Bugs, and to share both the astonishing real-life horror stories and the open scientific mysteries behind them. The discussion ranges from hairworm-infested crickets to fungi that lure new victims through chemical perfumes and even touches on whether humans could ever face a similar fate.

Key Discussion Points & Insights

1. What Are Real-life Zombies?

[06:25]

• Zombifier: An organism that manipulates the behavior of its host for its own benefit.
• Zombie: The manipulated host, acting against its natural interests.
• Example: Catching a cold changes your behavior for your own benefit, but a real “zombifier” benefits only the parasite.
  • Mindy Weisberger: "So it'd be like if I got sick and instead of going into my room and trying to sleep it off, I went and I licked everybody that I could lick in order to spread the cold." ([07:17])

2. The Fly in the Moonlit Field: Fungi as Zombifiers

[01:25 – 05:00]

• A spore lands on a fly, the fungus digests the fly from the inside, then manipulates it to climb high on a blade of grass to maximize spore dispersal.

• The fungus bursts through the fly’s body, releasing more spores and luring in new victims using chemical cues.

• Male flies are attracted to these fungus-bloated dead females due to their appearance and a "sexy fungal love perfume."

  • Bert Pinkerton: "It finds a place where it can climb, and it's thought that getting to a higher position is better for the fungus because it produces these spores that are released in kind of an explosive poof." ([02:45])

• Memorable Moment:

  • Bert Pinkerton: "It starts behaving like a fungus in a fly suit." ([02:45])
  • Mindy Weisberger: "All of this draws in new victims who, if everything works out, will soon be turned into their own fungal fly puppets." ([05:00])

3. Diversity of Zombifiers: Worms, Wasps, and More

[08:12 – 13:17]

• Hairworms in Crickets: Hairworms grow inside terrestrial insects but have to reproduce in water. They make insects find and leap into water so the worm can emerge, often grotesquely.

  • Mindy Weisberger: "So watching a cricket trying to swim in a pool of water while this long thread like worm is slowly over minutes, spooling out from its backside is something I highly recommend watching if, you know, you really want to squeak yourself out." ([09:19])

• Parasitic Wasps and Spiders: Certain wasps manipulate spiders to spin special "resting webs" as a cocoon for the wasp larva, which eventually kills the spider.

  • Bert Pinkerton: "The spider’s empty husk of a corpse drops to the ground. And the wasp larva builds its cocoon and sets itself up in the spider's final web to hang out until it becomes an adult wasp." ([13:05])

4. Major Scientific Mysteries Around Zombification

[10:12 – 14:50]
Three key questions:

1. Immune Evasion – How do zombifiers avoid or suppress their host’s immune system?
   • Bert Pinkerton: "How exactly are they telling their host immune system, no, there's nothing to see here?" ([10:34])
2. Timing and Triggers – What environmental cues initiate manipulative behavior (like night-time climbing for infected flies)?
   • Mindy Weisberger: "Are there things out in the environment that...trigger a fungal takeover?" ([11:32])
3. Mechanistic “Puppeteering” – What biochemical or hormonal changes drive these behaviors?
   • Example: Zombified spiders have brains flooded with ectosteroids, hormones that trigger molting web-spinning.
   • Bert Pinkerton: "It's almost like it's taking a page out of the spider's existing biochemistry... except this time it's not going to survive the process." ([13:37])

5. Why Study Zombie Bugs?

[14:50 – 21:44]

• Understanding how zombifiers manipulate behavior could shed light on fundamental questions of neuroscience and behavioral biology.
  • Bert Pinkerton: "This, in a lot of ways, is looking at really big questions about how behavior works, which... scientists are still piecing... together." ([18:38])

Potential Human Benefits

• Immunosuppression Insights: Could inspire medical research into immunosuppressive drugs.

  • Bert Pinkerton: "Looking at the immunosuppressive aspect of zombifiers is definitely something that is a huge area of interest because that could inform the development of immunosuppressive drugs..." ([19:27])

• Pest Control: Using viruses or fungi that zombify agricultural pests (e.g. caterpillars) as a targeted, less-toxic alternative to pesticides.

  • Bert Pinkerton: "So baculoviruses... have been deployed as a strategy for pest control... They're less toxic to the environment, they're not harmful to insects that are not their host species and they're not toxic to people." ([20:30])

6. Can Humans Be Zombified?

[22:13 – 26:10]

• Rabies: A classic example that alters mammalian behavior, including humans—causing aggression, biting, and hydrophobia.
• Toxoplasma gondii: Common in humans; subtle correlations suggest mild behavior changes (like increased risk-taking), but far less dramatic than in rodents.

  • Bert Pinkerton: "So hyena cubs that are infected with Toxoplasma gondii are bolder around lions and are more likely to be eaten by lions. Chimpanzees... lose their fear of jaguars. Some studies found that people who are infected with Toxoplasma gondii are more likely to make risky business decisions or be bolder in traffic…” ([24:00])

  • Mindy Weisberger: "So there could literally, at this moment, be zombifiers within us, shaping us in some way." ([25:41])

  • Bert Pinkerton: "It's entirely possible. But there are so many things that make us who we are that shape how we behave." ([25:49])

7. Ethical Concerns & Sci-Fi Scenarios

[21:44, 26:10]

• Could scientists engineer their own zombifiers to control pests—or might that spiral into a sci-fi disaster?
  • Bert Pinkerton: "Like you are describing the plot of a zombie movie right now where a team of scientists are working with their...zombie bugs...and they're like, oh, hey, wouldn't it be great if we could manufacture an artificial version of this zombie virus and release it into the wild? What could possibly go wrong?" ([21:52], [26:16])
  • Episode ends on a mock-drama riff about releasing zombie pathogens into the world.

Notable Quotes & Memorable Moments

• On fungal manipulation:
  "It starts behaving like a fungus in a fly suit."
  — Bert Pinkerton ([02:45])

• On the grossness factor:
  "So watching a cricket trying to swim in a pool of water while this long thread like worm is slowly over minutes, spooling out from its backside is something I highly recommend watching if, you know, you really want to squeak yourself out."
  — Mindy Weisberger ([09:19])

• On what zombification teaches us:
  "This, in a lot of ways, is looking at really big questions about how behavior works."
  — Bert Pinkerton ([18:38])

• On the dangers—and humor—of human-engineered zombifiers:
  "Like you are describing the plot of a zombie movie right now... What could possibly go wrong?"
  — Bert Pinkerton ([21:52])

Important Timestamps

• [01:25] Dramatic opening: The zombified fly in the moonlit field
• [05:00] Mindy names these as “real-life zombies” and introduces her research
• [06:25] Defining ‘zombifier’ and ‘zombie’ in biology
• [08:12] Favorite/worst zombifiers (hairworms in crickets)
• [10:12] Major scientific mysteries about zombification
• [13:05] Parasitic wasps and spider puppet-masters
• [18:38] Why study this: what we learn about behavior and immunology
• [20:30] Pest control applications of zombifier research
• [22:30] Could humans be zombie-ized? (rabies, Toxoplasma gondii)
• [26:10] Comic sci-fi riff on zombie bug apocalypse

Further Reading

Rise of the Zombie Bugs by Mindy Weisberger (for in-depth stories and science)

Summary prepared for listeners seeking a rich, structured understanding of cutting-edge science at the spooky intersection of entomology, behavior, and infectious disease—without any ad breaks or fluff.