Ologies with Alie Ward
Episode: Blattodeology (YES, COCKROACHES) with Dominic Evangelista
Guest: Dr. Dominic Evangelista, Assistant Professor, University of Illinois Urbana-Champaign
Release Date: October 15, 2025
Main Theme
"Cockroach, My Beloved":
In this Spooktober-themed deep dive, science humorist Alie Ward confronts one of the most reviled creatures on the planet—the cockroach. Joined by cockroach expert (blattodeologist) Dr. Dominic Evangelista, the episode sets out to challenge disgust and fear, unveiling the surprising diversity, extraordinary biology, parental prowess, and misunderstood reputation of Blattodea. From evolutionary origins and glittering forest dwellers to pest control realities and even medicinal cockroach creams, it’s a jam-packed celebration of one of the planet’s most successful survivors.
Key Discussion Points & Insights
1. Cockroach Basics & Reputation
- Cockroach Diversity: There are about 7,000 described species, likely many more; only 10–20 ever interact with humans as pests. The rest avoid us entirely.
- "99.904% of cockroaches will never be in your toaster." [05:27]
- Species Most People Know: The American and German cockroaches, neither of which originated where their names suggest.
- The vast majority live out in tropical rainforests, deserts, grasslands.
2. Evolution and Taxonomy
- Termites Are Cockroaches: Recent science reclassifies termites as highly social cockroaches, not a separate order.
- "Termites are actually just fancy cockroaches." [06:03]
- Varied Social Structures: Only termites are truly eusocial (queen/king, castes), but other roaches practice subsocial behavior or display parental care.
- Some cockroach “clans” fare better socially, showing reduced appetite and shyness in isolation (French study "Weight of the Clan," 2009). [07:55]
3. Defining Features
- Luggage Handbags for Eggs: Cockroach mothers create leathery egg cases (ootheca), distinct from the foamy cases mantids produce.
- "They craft [their egg cases] with their genitals, and they’re stuffed... with their own children." [09:26]
- Hidden Head and Flat Body: Pronotum (shield) covers their head; they evolved for hiding in crevices.
- Sensory Butts (Cerci): Two finger-like appendages sense vibrations/air movement, key for predator evasion.
- "It’s like you having a nose or eyes right on your hiney." [11:54]
4. Wild Roaches: Superpowers & Habitats
- Olympian Agility: Forest cockroaches are acrobatic, fast, and hard to catch (“American Ninja Warrior” vibes).
- Tiny and Massive:
- Smallest: About 2 mm, e.g., Attaphila fungicola, which rides leafcutter ants during nuptial flights.
- “Do they ride them like little ponies?” “I think they do, yeah.” [15:10]
- Largest: Megaloblatta (hand-sized wingspan), and the Australian burrowing cockroach (closed-fist size). [16:31]
- Smallest: About 2 mm, e.g., Attaphila fungicola, which rides leafcutter ants during nuptial flights.
5. Evolution of Wings & Sexual Behavior
- Mystery of Tiny Wings: Many species have short, nubby, even flightless wings—an ongoing area of research.
- Mating Rituals: Elaborate—males use wings to position the female and offer “copulatory gifts” made of uric acid crystals (urine).
- "Cockroaches are the only animals, other than humans, that give sexual golden showers." [20:38]
- Symbiosis and Superpower: Cockroaches lack conventional urine; their endosymbiotic bacteria recycle uric acids, turning waste into protein.
- "Cockroaches don’t actually pee... they recycle [urates]." [22:46]
6. Behavioral Ecology & Diet
- Nocturnal/Diurnal Split: Most cockroaches are nocturnal, but colorful species are likely diurnal.
- Diet:
- Wild cockroaches are primarily detritivores: leaf litter, fungus, some specialize in wood, and cave dwellers may eat guano.
- Some are even nectar feeders or pollinators. [28:42]
- Indestructible Myths: Pest species persist due to adaptability, hiding, and human environments—eating glue, dead skin, even book bindings.
7. Pest Species and Human Abatement
- Origins: American cockroaches likely from Africa; German cockroaches from Southeast Asia; "oriental cockroaches" are from Crimea.
- Pest Control Tips:
- Clean up, seal gaps (especially plumbing), run a dehumidifier. Pesticides only kill visible ones; long term, discouraging their survival is most important.
- Damp Living: American cockroaches are water-resistant, can swim, and traverse plumbing.
8. Polarizing Anatomy & Smells
- Genital Architecture: Male genitalia are ornate and asymmetrical (clamps, hooks, spines—artworthy!).
- Odor: Cockroaches release musty, sometimes skunky odors, especially en masse; some act as "skunk roaches".
- Are They Clean? Yes and no—cockroaches groom constantly and their cuticle may have antimicrobials, but pest species pick up filth from their environment.
- "They're not inherently dirty, but just like anything else that moves around and interacts with its environment, it might pick up some things." [44:21]
9. Cockroaches in Culture and Medicine
- Edibility & Medicine:
- Roaches are eaten in some cultures (deep-fried), and their creams, teas, and pain patches are used medicinally, especially in China and Latin America.
- "The whole bit about them not peeing but saving their pee in their bodies makes them seem not that appetizing." [47:12]
- Pop Culture:
- Joe’s Apartment (movie), La Cucaracha (song), and Kafka’s The Metamorphosis are all referenced—though Dr. Evangelista finds these portrayals inauthentic and American-roach-centric.
10. Parental Skills & Reproduction
- Diverse Births:
- Some lay eggs in cases, others do live birth; some nymphs pierce mom’s exoskeleton and drink her blood; certain species even secrete “cockroach milk.” [52:29]
- "That's a dedicated mom." [52:28]
- Parental Care: Subsocial species guard, feed, and even "inoculate" babies via fecal/oral transfers, much like termite relatives.
11. Population & Coexistence
- If You See One…: There are usually more. For German cockroaches: “about 100 more for every one you see.” [53:43]
- Ambassador Roaches:
- Madagascar hissing cockroaches are calm, easy to handle, and make great ambassador species for exposure therapy and education.
12. Conservation/Ecology
- Crucial Role: Cockroaches are a key biomass in tropical canopies, important prey for birds and lizards, critical for nutrient cycling as detritivores.
- "Cockroaches as a whole are hugely important to certain ecosystems... the largest proportion of animal biomass in tropical rainforest canopies are cockroaches." [67:03]
13. Why the Disgust? Why Love Them?
- Social conditioning and unpredictability drive fear/disgust, but learning about their diversity and ecological role can shift perspectives.
- "They are some of the best mothers in the animal kingdom." [60:13]
- Check Dr. Evangelista’s "roachbrain" iNaturalist for glamor shots of beautiful cockroaches.
Notable Quotes (with Timestamps)
-
On Cockroach Reputation:
"Those 10 species that we might come across in our homes give a bad reputation to all of them." —Dr. Dominic Evangelista [04:08] -
On Sociality:
"Only termites are what we call eusocial... Other cockroaches, they do have levels of sociality, but not to that highly advanced organized level." —Dr. Dominic Evangelista [07:14] -
On Mating Rituals:
"Cockroaches are the only animals, other than humans, that give sexual golden showers." —Dr. Dominic Evangelista [20:38] -
On Anatomy:
"Their genitalia are totally different on the left and the right... complicated three dimensional clamp-like structures." —Dr. Dominic Evangelista [34:51] -
On Pest Survival:
"We have cockroaches in our building, and this is probably no way to get rid of them... eventually they'll find some kind of food." —Dr. Dominic Evangelista [29:48] -
On Cleanliness:
"They're constantly grooming themselves. Their antenna, their legs... and have antimicrobial properties on their exoskeleton." —Dr. Dominic Evangelista [43:00] -
On Parental Care:
"Some of them have small colonies... guarded by a matriarch." —Dr. Dominic Evangelista [07:55] -
On Conservation Guilt:
"In order to achieve [conservation] I have to kill a lot of cockroaches... it doesn’t feel great." —Dr. Dominic Evangelista [64:42] -
Career Inspiration/Advice:
"If you want a job, you sometimes can't watch a door and wait for it to open—you gotta cram in through the cracks like a cockroach." —Allie Ward [End]
Important Timestamps
- What defines a cockroach? [04:32–10:34]
- Termites are cockroaches: [06:01–07:14]
- Cockroach mating/sexual ritual details: [20:18–24:03]
- Wild species (tiny to giant): [14:46–16:59]
- Lab and pest survival stories: [29:29–33:38]
- Cockroach parental care/live birth: [50:18–52:31]
- Cockroaches in pop culture: [54:26–56:20]
- Strategies for learning to love cockroaches: [59:52–61:00]
- Ambassador species (Madagascar hissing cockroach): [62:28–63:17]
- Conservation/ecosystem role: [65:42–67:03]
Memorable Moments
- Cockroach riding ants like ponies [15:10], complete with a citation and irresistible mental image.
- Cockroach milk and “vampire” nursing—bonus content promised for future episode. [52:31]
- Urine-based mating gifts—a rare example of sexual behavior found in both roaches and giraffes.
- Pain patch anecdote: Allie’s revelation about unknowingly sleeping with cockroach-ingredient pain patches. [48:40–49:17]
- "If you see one roach..."—the classic dread: for many species, if you see one, you may have 100 hidden. [53:05–53:43]
Summary Table: Cockroach Portrait
| What Most People Think | What’s Actually True | |---------------------------|------------------------------------------------| | Dirty, persistent pests | 99%+ are nowhere near humans, play vital ecological roles | | Indestructible | Pest resilience is more about opportunity + adaptability | | Creepy, “bad” sociality | Range of advanced social behaviors; some are model mothers | | Monotonous, ugly species | Wild rainbow of color, shape, size—many are beautiful, charismatic | | Unhealthy, infectious | Some have antibiotic properties; regularly used in medicine |
Quick Tips on Coexistence and Control
- Deterring Home Invaders: Clean up, seal plumbing gaps, use dehumidifiers
- Pet Ambassador: Madagascar Hissing Roach—gentle, slow, great with kids (adults may need more exposure therapy!)
- Appreciating Roaches: Look up “roachbrain” on iNaturalist for stunning cockroach portraits
- Ecosystem Reminder: If you hate household pests, remember the rainforests would collapse without their cockroach “clean-up crew” cousins.
Final Call
Allie ends with encouragement to see cockroach tenacity as an aspirational metaphor—be the roach; find your way through, outlast adversity, keep your antenna (and side of things) clean.
For more info:
- Dr. Evangelista’s lab: roachbrain.com
- Beautiful cockroach photos: iNaturalist @roachbrain
“If you want a job, you sometimes can't watch a door and wait for it to open. You gotta cram in through the cracks like a cockroach.” – Allie Ward [Epilogue]