While cockroaches may not be the most romantic animal, the ‘Salganea taiwanensis’ species is sexually, socially and genetically monogamous. The reason behind their monogamy is quite unique: After finding a mate, these roaches spend the rest of their lives residing in rotten wood, which gives them no opportunity to find any other mates…
— from “Which Animals Are Monogamous Rather Than Mating For Life?” by Seth Millstein on SentientMedia.org, April 2024.
You learn something new every day, my dad used to say, and that certainly seems to be true for me, so long as my internet connection is working.
But I actually learned about the Salganea taiwanensis cockroach’s mating habits from a different source. The radio.
Yesterday, Ari Daniel — a science reporter with NPR — shared a story about a species of Asian cockroach that reportedly stays true to their chosen partner over the long haul.
I knew that certain birds pair up and figure out how to make things work with the same partner for their entire lives. And also certain mammals, and fish. Even humans, occasionally. But I had never heard of bugs doing it, other than in that song by Cole Porter…
And that’s why birds do it, bees do it
Even educated fleas do it
Let’s do it, let’s fall in love
I always thought Cole Porter was making a joke. Not entirely, it would appear.
The wood-eating Salganea taiwanensis cockroaches live in the forests of Okinawa, among other places, and a male and female who have a thing for one another will burrow into some rotting wood and create a little shared living space.
Then something kind of weird happens. They chew off each other’s wings, and eat them.
To make sure neither one flies off at the first sign of marital discord, I would guess.
They then have children and raise them together in their little rotting paradise.
But scientists wanted to know if these bugs had a “pair bond” — that is, if they were paired for life — or if they were just hanging out together until the kids were out of the house. So they gathered up some cockroach pairs, some of which had eaten each other’s wings, and some who still had their wings intact (and were presumably just shacking up.) The scientists supplied the couples with makeshift nests in laboratory cages, and then introduced a “third party” to tempt the bugs into an illicit affair. Someone well-dressed, and good-looking, with a little money?
The folks participating in the NPR show were, at this point, watching a video, but of course I couldn’t see what they were seeing, because it was radio. Apparently, when an intruder gets introduced to a couple who still have their wings intact, the newcomer is treated like just another guy, or gal, who happened to drop by.
From the NPR website:
[Scientist Nate Lo] calls up a video to show what happened. A pair of roaches that both still have their wings appears on the screen. When the intruder enters the nest, there’s no aggression or fuss. The interloper — whether male or female — is allowed to stay.
“You see, they’re just very relaxed about it,” says Lo.
But when he calls up a roach pair that had eaten one another’s wings, “both the male and the female attack,” he observes, by ramming the intruder. “They also wiggle their butts and hit them with their butts. They’re quite aggressive little creatures.”
“You can see the intruder’s very worried,” adds Lo. “It’s trying to escape because it knows that it’s in trouble. So that suggests they don’t want to have a third wheel. It’s like they’ve got this pact.”
It’s a pact that the researchers say looks a lot like a ‘pair bond., in which the two roaches, upon eating each other’s wings, become highly aggressive towards outsiders and only tolerant of their partner…
The scientists apparently find these abilities — to be faithful to one’s partner, and to cooperate on beating up intruders who threaten the relationship — to be slightly unbelievable in an insect with a brain smaller than a sunflower seed.
In my personal experience, one’s brain has very little to do with falling in love.
Anyway, they captured it on video. So that’s some kind of proof. But it was on the radio, so I didn’t actually see the proof.
When Darlene and I got married, we just made a vague promise — in front of our families and friends — to keep our ‘pair bond’ sacred until death do us part. Maybe if we had eaten each other’s wings, the marriage would have lasted that long.
But we didn’t have wings.
We each had our own automobile, however.
According to several articles I found online, scientists have calculated that the human brain contains about 100 billion neurons, while a cockroach brain contains only about 1 million neurons. Scientists sometimes hold up the number of neurons as evidence that humans are more intelligent than cockroaches, but I think all those extra neurons only make us more confused.
Underrated writer Louis Cannon grew up in the vast American West, although his ex-wife, given the slightest opportunity, will deny that he ever grew up at all. You can read more stories on his Substack account.