Learning from Crayfish: Is America Over-reacting?

Catching Crayfish, with Coronavirus-Conscious Caution:  Flying the Flag of Healthcare, Is America Recklessly Over-reacting to its own Peril?

Dr. James J. S. Johnson


Turn not to the right hand nor to the left: remove thy foot from evil.  (Proverbs 4:27)

Is America over-reacting to the Wuhan Virus epidemic/pandemic?  If so, how much peril does America recklessly face, while flying the flag of healthcare “carefulness”?

Recently, Dr. Darren Schulte, a medical doctor (of Apixio, a health analytics organization), provided a cautionary warning about over-reacting to the Coronavirus pandemic.(1) Dr. Schulte’s timely “heads-up” counsel is considered, below—along with a description of a recreational activity that some can attempt, depending on location (and availability) of lotic water-dwelling crayfish.

There are many indications that his concerns and admonitions should have been heeded in what is now called the “Coronavirus response”—but it is not too late to consider some of his big-picture healthcare analysis.

In many infectious diseases, the immune system’s reaction to a virus, bacteria, or other pathogen can cause greater harm to the infected individual than the pathogen itself. Sepsis is a deadly example of this phenomenon. Triggered by an infection, the immune system overreacts, releasing chemicals called cytokines that make blood vessels become leaky. That can ultimately reduce oxygen delivery to vital organs, which may cause organ failure. Sepsis kills more than 10 million people a year. The Covid-19 epidemic is something like sepsis: the reaction by the media and government is likely to produce more harm to societies around the globe than the virus, possibly for many years to come.

I’m not trying to downplay the impact of this virus, officially known as SARS-Cov-2. Fever, cough, and shortness of breath are the primary symptoms. They can appear two to 14 days after exposure, though many people infected with the virus don’t experience any symptoms at all. Based on the data we have so far, the virus appears to be more deadly than the influenza (flu) virus. (1)

Dr. Schulte’s cautionary warning (about over-reacting to the Coronavirus pandemic) was informed by the historical context of America’s public health realities. This historical big-picture includes refusing to over-react to ordinary flu virus “seasons”, as an excuse to maim America’s society by amputating our economic assets, inflicting enormous harms to our livelihood needs (and menacing other threats to our lives and liberties).

We have learned to live with the flu, which can cause up to 80,000 deaths a year in the U.S. and between 300,000 and 650,000 worldwide. It doesn’t invoke widespread fear, dread, and hysteria. Life goes on.

People go out in public, eat at restaurants, drink in bars, fly in planes, take mass transit, attend sporting events, and congregate in other large indoor settings. We cope with it by washing our hands with soap and water for at least 20 seconds, avoiding close contact with people who are sick, and covering coughs and sneezes.

Flu, of course, is a known quantity, whereas Covid-19 is new and not yet well understood. Unfamiliar infectious diseases are scary. Plus we don’t have a vaccine for coronavirus, as we do for influenza. We do have antiviral medications [e.g., time-tested hydroxychloroquine, augmented by azithromycin and/or zinc], which might be effective against coronavirus, but it is too early to tell.

It is impossible to run a test to compare the state of the world with the public health measures that are being undertaken with what would have happened without them. Yet we should take a hard look at the costs and benefits of the actions taken.(1)

Dr. Schulte continued with counsel for what to do, now.

What’s the appropriate response to Covid-19?

I believe we should counsel individuals to continue going about their daily lives while taking proper and prudent precautions until we learn more about its long-term public health risks of this disease.

We should try to balance the public health and safety concerns with disruptions in daily activities. Quarantining individuals who have been exposed to the virus or who have underlying health risks makes sense, as does adhering to prudent measures like staying at home if you feel sick, washing your hands regularly, covering your mouth when coughing and sneezing, and avoiding large social gatherings. All of these can attenuate the spread of the virus.

But we must be measured in our actions so we don’t end up causing more lasting harm than good as we try to protect ourselves and our communities from a new — and scary — infectious disease.(1) [emphasis added]

Over-reacting can be embarrassing, self-inflicting consequences worse than whatever one is reacting to.

And with crayfish—at least some of them—it can be fatal.



During my junior high years, living in a rural part of Maryland, I learned the art of catching crayfish.   (Nowadays I just eat them at restaurants!)   As a teenager, I was neither an astacologist (crayfish scientist) nor a serious catcher of crayfish (which is the same crustacean known to some as “mudbug” and in Louisiana as “crawfish”), so I did not use a “crayfish trap”.  Rather, as described below, I used a homemade dipping net, to catch those greenish critters that looked like lobsters.

Crayfish like drainage ditches and slow-moving streams, especially those with banks that are shaped in ways that provide hiding places for crayfish (and habitat for what crayfish eat [nocturnally], including underwater rocks or logs or roots.(2)

After a heavy rainfall the velocity of stream currents may increase, as it drains, but crayfish can act to maintain their position at the edge of such drainage.

Crayfish … help maintain position [in face of faster current flow] by altering body posture to counteract the effect of drag when exposed to an increase in current velocity.(3)

Crayfish care about staying and defending their “home turf”  –  i.e., they are territorial, and some will fight to defend a favorite stream-bank crevice.(3)

Crayfish are omnivores – they emerge from their hiding places, especially when it is dark—due to nocturnal half of the diurnal cycle, i.e., to use Bob Webel’s TNT (Montrose) terminology, from “dusk to dawn”(2)—or due to cloud-cover (on days when sunlight is scarce), to find and feed on freshwater snails, fish eggs, tadpoles, worms, algae, grains, and other plant material.(3)


The dominating influence of crayfish (i.e., what Paul Miller and Björn Malmquist call “keystone predators”) in the food webs of drainage ditches and sluggish stream-waters (where they live), is produced directly, as predators, and indirectly, by eating riparian plant cover used by aquatic invertebrates.(3),(4)

Drainage ditches are a favorite habitat of crayfish, not just in Maryland.

Ditches are of course just man-made sloughs [pooled stream-water that only moves slowly], but they are important to the survival of many species of life in the state.  Ditches are necessary for allowing rain runoff much of the year, and wherever water is present for half the year or more there are likely to be populations of crawfishes  and other invertebrates, as well as their predators such as frogs, snakes, and turtles.  Even shallow ditches may be home to several species of crawfish, some quite uncommon and localized in distribution.(5)

Where I (then) lived, in rural Baltimore County,  there was a bridge with a huge drainage pipe that allowed stream-water to flow in irregular patterns, around large and small rocks, so that the stream bank had indentations and crevices where the waterflow was somewhat shielded, providing places for small creatures (like baby fish and insect larvae) to avoid being swept downstream, though crayfish lurked nearby, always hungry for something small to eat, whether it be plant material or aquatic invertebrates.

When moving on land crayfish crawl, using their legs.  But, when underwater, they “swim” or “paddle”, using their legs and when needed, the tail fan.  Rapid flipping of the crayfish tail enables the crayfish to suddenly propel itself backward  — it appears to “jump backwards” in the water.  This can provide a quick exit from anything facially threatening the crayfish.

Of course, the crayfish themselves were shy about large disturbances in the water, so wading into the stream (which might be ankle-deep to knee-deep) would scare crayfish into hiding places, some of which were located under the bridge or in underwater burrows nearby.

If you splash a stone into the water directly in front of a crayfish it would jet backwards to escape.  The escape maneuver was so reflexive and quick that the crayfish never looked before it “jumped” backward in the water, to escape whatever the perceived danger was in front of it.

After learning this crayfish habit it became apparent that crayfish could be easily caught, by taking advantage of this “knee-jerk” reaction, with a home-made “net”.  So how did we catch crayfish, down by the drainage pipe that conveyed stream-water under the bridge?

First, make a “net” to catch the crayfish with.  Reshape (by bending) a coat hanger into the shape of a lollipop profile, i.e., a straight line (for a handle) that is curved into a circle.  The resulting shape of the coat hanger resembles a somewhat small version of the frame of a tennis racquet (or badminton racquet), with the “loop” (circle or oval) part being about the size (circumference) of a soccer ball, easily enough room for catching a large or small crayfish.

The metal frame needs a net, so you tear apart an expendable T-shirt. Then you thread it onto the circular “loop” part of the reshaped coat hanger.  Ideally the result is somewhat like a dipping net used for an aquarium.

The coat-hanger “dipping net” is the tool to be used for catching (netting) the crayfish, but keep in mind that a crayfish will try to exit if caught, so you need a bucket of water to “land” your catch if and when you catch one.  So you need to bring a bucket (or a pail will do!) that is half-filled with water, and it must be positioned near the spot where you expect to net your crayfish.

The largest crayfishes, catchable with such racquet-nets, are about the size of lobsters that you get at Red Lobster restaurants.

The next trick is to get a crayfish to “jump” into your net, in the stream-water, just before you jerk the net up and out of the water (so the crayfish can’t exit your net, upon realizing that he or she is caught!).

But how do you entice a shy crayfish to “jump” into your net?  Actually, it’s not very difficult, although it requires sequenced (and quick) timing as you perform two rapid movements.

With your net ready to “stab” the water just behind the crayfish (i.e., where his or her tail is located), drop a clod of dirt (or a small rock) about 6 inches in front of the crayfish’s head and front claws.  Instantly plunge your net behind the crayfish – which is now “jumping” backward to avoid whatever you dropped into the water.  Then quickly jerk the net up out of the water – you should have the crayfish secured inside your net, for a moment at least, so now you quickly dump the net into your bucket of water, and shake the crayfish loose from the net.

If your bucket is deep enough the crayfish is now covered in water, yet the water level needs to be low enough that the crayfish cannot swim to the top and then crawl out over the brim, to escape involuntary confinement.

Ironically, it was the crayfish’s “safety reflex” habit  —  the automatic “jump-back” reaction  —  that got the crayfish captured!


Now that you have a captive crayfish you need to feed it, to keep it alive, or else eat it (!) as you might a lobster, or just release it.  “Catch and release” is what I recommend.

But what does catching a crayfish have to do with the adventure of living the Christian life? 

The crayfish illustrates the danger of carelessly over-reacting to a perceived danger.  Because the crayfish is startled by the rock dropped (into water facing the crayfish), it automatically reacts by “jumping” backward  –  without checking to see if a net is waiting there, to capture it! Since the Christian life involves a lot of balancing, we need to be careful about over-reacting to this or that.

Regarding the need to avoid over-reacting, as a Christian who strives to honor God in this life, see Dr. Charles Ryrie’s indispensable guidebook, Balancing The Christian Life.(6)

Over-reacting involves moving recklessly from one extreme to its opposite. Obviously, that can apply to what Dr. Schulte calls over-reacting to the Coronavirus pandemic.(1)

Meanwhile, next time you catch a crayfish, or eat a plateful at a kräftskiva (Swedish crayfish party), or eat one at a Cajun restaurant, remember this lesson: don’t carelessly over-react!   —   review the big picture, and maintain a Biblical balance in whatever you are doing.(7)



1.     Schulte, D. 2020. The novel coronavirus is a serious threat. We need to prepare, not overreact. Stat News (March 16, 2020), posted at https://www.statnews.com/2020/03/16/coronavirus-serious-threat-prepare-not-overreact/ — accessed April 13, 2020.

2. Actually, too many astacologists—for many years when “lab experiments” overshadowed “field studies”—observed crayfish under unrealistically artificial conditions, learning nothing that was representative of how crayfish behave in the wild. Johnson, James J. S. 2015. Crayfish, Caribou, and Scientific Evidence in the Wild. Acts & Facts. 44(6):20, posted atwww.icr.org/article/crayfish-caribou-scientific-evidence/ .

3. Giller, P. S., and B. 2008. Malmqvist. The Biology of Streams and Rivers.Oxford University Press, 122, 131-132, 204 (including quotation from page 122).

4. “Ecosystem engineering” explanations exhibit a theoretical improvement on prior concepts of “keystone species”, yet both approaches fail to identify the true cause and logic underlying animal successes in filling various eco-niches and habitats. Johnson, James J. S. 2019. Ecosystem Engineering Explanations Miss the Mark. Acts & Facts. 48(3):20-21, posted at  https://www.icr.org/article/ecosystem-engineering-explanations-miss-the-mark  .

5. Walls, J. G. 2009. Crawfish of Louisiana. Baton Rouge, LA: Louisiana State University Press, 35-36.

6. Ryrie, Charles C. Balancing the Christian Life. Chicago: Moody Press, 1994 (252 pages). Thankfully, this book was provided to me, when I was a teenager, by my youth/college pastor, Chaplain Bob Webel.

6. 1st Corinthians 10:31. Within America, festive summer-time kräftskiva(crayfish party) events are sometimes hosted by IKEA stores.

One thought on “Learning from Crayfish: Is America Over-reacting?

  1. Simply fantastic! Superb instructions! Well written! Still,
    if you don’t mind, I will devour
    food that comes from known sources of absolute cleanliness or from providers that display the same. Thanks for the invitation, anyway.

    Liked by 1 person

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