Flea Odyssey in Eight Vignettes

Vignette 1: Long Time Ago

Some paleontologists believe that the earliest ancestors of today's flea may have appeared—little by little, no doubt—in the Devonian period of the Paleozoic Era, between roughly 419 and 359 million years ago (Mya). Fossilized specimens from the Devonian would happily confirm their hypotheses, but the oldest known fossil remains of the species date from the post-dinosaurian period known as the Paleogene, which lasted from 66 to 23 Mya. To the benefit of the flea—as if it were part of a master plan—the Paleogene witnessed the evolution of many species of small fur-bearing mammals, including numerous rodents that could serve as hosts to the little ectoparasites, and whose nests and bedding sites would have provided their offspring convenient cover to protect them from predators.1 Diaphanous images of a few fleas have been found in amber stone, which is the fossilized resin of certain now-extinct tree species that are native to the rim of the Baltic Sea (44 Mya), the eastern Mediterranean Levant, and the mountains of the Dominican Republic (25 Mya), but there are not enough to provide answers to some of the flea's evolutionary history.2 For example, it is highly unlikely that the morphology of the flea was static for all those millions of years since it's principal hosts must have changed theirs, but how and when, and especially why, remain securely hidden—at least for the present.

Regarding the ancient biography of the flea from another angle, the order survived on rodents, a few birds, and perhaps a few reptiles for almost all of that hypothetical 359 Mya sojourn before the first tribes of Homo sapiens evolved, bringing with them languages in which to complain about them. Next, it may have been a mere 200,000 years ago when Homo neandethalensis, among others, began to wear clothes,3 which was a real boon to insects that preferred human blood, because the encasement created protection from daytime heat for traveling fleas, a platform from which to enjoy nighttime bloodsucking, and dry beds to protect them from rain as well as predators during the day.

Somehow they sensed what they had to do: find a host from which a female flea could sip enough protein-rich blood to enable her to produce 3 to 8 eggs, which within 48 hours would yield an equal number of larvae (worms), which in turn would prevail for 9 to 15 days, then segue into pupae for an indeterminate period, and finally emerge into adulthood. On average, a majority of fleas require from 30 to 75 days for a complete life cycle, although within the past hundred years entomologists have found many fleas with much longer or shorter lifespans.

On the whole, a flea's life is a chancy venture.


Vignette 2: Fade to the Biblical Age

Some linguists maintain that the beginning of verbal communication between you and me was coincident with the emergence of our own early species, Homo sapiens. Wouldn't it be interesting to learn how our very first ancestors coped with fleas verbally—along with other universal nuisances such as mosquitoes. The answer is out of our reach, of course, but . . . would it be printable?

In the Old Testament the flea was a symbol of humility and insignificance. David (c. 1040–c. 970 BCE), a young shepherd who was destined to become King of Israel, was feared and envied by his predecessor, King Saul. With assassination in mind, Saul pursued David with an army of three thousand men, intent upon celebrating his demise along with his few friends. When they met, the youth defended himself against Saul's slow-witted display of might by pointing out that he was "poor and insignificant," and ridiculed Saul's audacity with the image of himself as no more powerful than a flea: What was the king of Israel after? The dog is dead! The fleas are gone! In a later confrontation he taunted Saul again: "The King of Israel has come out to seek a single flea as if he were hunting partridges in the mountains?" Saul would have known that partridges were upland Eurasian game birds which are found only in open fields and prairies.4


Vignette 3: Moses' and Aristotle's 'Dusty' Theory

The deep and durable Biblical doctrine that God created humankind out of dust sidestepped the logical paradox that life can only proceed from life. Thus the assumption that the lowest forms of life, which we call insects—the word refers to the segmentation of the diminutive species' bodies—can only have emerged from dust or worse, was confirmed by the earliest Greek philosophers and defined by Aristotle, on the premises that the insect has no heart, no blood, no brain, and apparently no reproductive organs. It explains the story of the Third Plague in the Captivity, recounted in Exodus 8:16-19. The Lord directs Moses to command Aaron: "Stretch out your staff and strike the dust of the earth, that it may become gnats [including fleas] through all the land of Egypt."

For more than two thousand years the doctrines of the proto-scientist Aristotle (384-322 BCE) concerning animal life, formed the bases for an unending variety of tropes on the Greek philosopher's Ladder of Life. "So with animals," he had written, "some spring from parent animals according to their kind, whilst others grow spontaneously and not from kindred stock; and of these instances of spontaneous generation some come from putrefying earth or vegetable matter, as is the case with a number of insects." Such as the flea.5


Vignette 4: How Narrow is the Pipe Whereby it Sucketh!

Aurelius Augustinus Hipponensis (354–430 CE), properly known as Augustine, Bishop of Hippo6, but longer and more widely as St. Augustine. His works are still widely read and admired for his profoundly insightful, verse-by-verse meditations on each of the 150 Psalms, which he originally prepared and delivered orally to his catechumens. Fortunately, they were written down by teams of scribes for publication. In all of his writings, his literary style was that of the common man, embellished with thoughtful re-phrasings and topical alternatives to the original Hebrew transcriptions, that would seize the lagging attention of his pupils, and sear the truths into their memories.

For example, in Psalm 148 a reverent regard for all God's creatures is preached, regardless of their positive or negative values to humans. Verse 10 of the 14 verses in Psalm 148, for example, lauded "Animals wild and tame, creatures that crawl and birds that fly." No particular species were named in the original version of the Psalm, so Augustine arbitrarily chose the flea and the mosquito to represent the smallest and least imposing of the Divine Creator's works. They were certainly among the most ubiquitous living creations of all time, each being—to paraphrase a modern pedagogical cliché—a "teachable species."

The homilist urged his young pupils to think about this:7 "Who has arranged the limbs of a flea and a gnat [mosquito] that they should have their proper order, life, motion? . . . If you consider . . . that animation of life whereby it moves; how does it shun death, love life, seek pleasures, avoid pain, exert various senses, vigorously use movements suitable to itself!"

Then, abruptly, came his own tagline: See, he said, "how narrow is the pipe whereby it sucketh!" Here was knowledge, truth of Divine Creation, forever hidden from unassisted sight. Surely that would have jerked the drowsiest of his pupils to attention. Few if any of them could ever have imagined, much less distinguished, those "sucking parts," yet no one could ignore the fact that they were what produced that persistently irritating, swollen little red spot on one's skin, with a darker hole at its center—not a bite at all, but a puncture. It sounds as if their homilist had seen those parts himself.

But how? The microscope was still more than a thousand years in the future. But if the prelate had thoroughly examined the flea's anatomy, it could have been with a simple magnifying glass of the type often used by craftsmen such as engravers, A sample hand lens was found in a shop at Pompeii that was buried deeply beneath volcanic ash and pumice by the eruption of Mount Vesuvius in the year 79 CE. Also, it was sometimes used to light fires. (Meriwether Lewis took along eight dozen "burning glasses" to bestow as gifts upon natives the Corps of Discovery met along the expedition's route.)

Simple magnifying glasses were sometimes used to locate fleas on one's own body before they began feeding. Indeed, early in the 17th century they were commercially sold as vitres pulicaria—"flea glasses." The only other way Augustine could have learned of the smallest organ on the smallest insect would have been to rely on a myopic or extremely near-sighted acquaintance to make a visual examination in his behalf.


Vignette 5: A Flea Defies Gender and Beauty


"Woman with a Flea" (ca 1638)

Woman crushing a flea between her fingernails

This image is in the public domain.

Oil on canvas (90 cm by 120cm) Georges de La Tour (1593–1652) Nancy, Lorraine, France

During the Renaissance (1450–1600), Baroque (1600–1750), and Romantic (1750–1900) Eras, fleas were often treated as literary or artistic pets by painters, poets and essayists, who used the predictably energetic insects to highlight social, moral, or erotic themes—none of which are present in this depiction.

A painterly style known as chiaroscuro (KEE-ah-ro SKOO-ro; Italian for "light–dark") used a single light source to subtly create deep shadows to subtly frame the subject's space on the canvas. George de La Tour of Lorraine, France, was the acknowledged master of the technique. In the above painting it tells us that this young woman, with her hair still neatly tucked beneath a linen coif or nightcap, has been aroused from sleep by at least one flea that sought to sip a drop of her blood. It is a distraction that she, like everyone else on earth, simply has to put up with.

Her fists—unbecoming a pretty woman—are poised in flea-crushing curls with thumb-nails opposed, ready to squeeze the unwelcome intruder between them. She has doused one nail with a deep drop of spittle to impede the flea's escape—a flea can't swim in anything. Her impassive expression betrays no anger, no fear, no moral repugnance. The otherwise voiceless Siphonaptera will die with a whispered "click."


Vignette 6: Work Up Imagination to the State of Vision

"A Ghost of a Flea" circa 1819

William Blake (1757–1827)

Odd looking creature walking upright

Tempera, heightened with gold on a mahogany panel. A miniature, measuring 8.42 x 6.3 in (21.4 x 16.2 cm). Bequeathed to the Tate Britain Gallery in 1949 by W. Graham Robertson.

With its muscular torso and legs, faintly tattooed shoulders and arms, a slightly oversized head with small sharp horns and a tongue shaped like a siphon, the ghost, poised for a cosmic leap, looks out upon nearby stars at the fringe of the galaxy that hosts our solar system. The American art historian Hope Werness has suggested that Blake's inner vision of his subject may have been inspired by Robert Hooke's enlargement of his microscopic image (See figure in A Closer Look).8

The artist was said to have exclaimed to an acquaintance at the moment he began work on his vision: "There he comes! his eager tongue whisking out of his mouth, a cup in his hand to hold blood, and covered with a scaly skin of gold and green." Thus does Blake's image become a visual metaphor for Hooke's monstrous depiction of the tiny but well-built parasite. As Blake once explained to a young artist, "you have only to work up imagination to the state of vision and the thing is done."

William Blake was a seminal force in the rise of English era of Romanticism, which overlapped in the young U.S. with the Federalist and Post-Federalist eras. He was the senior by about fifteen years of the Lake Country poets, William Wordsworth, Samuel Taylor Coleridge, and Robert Southey. Coincidentally, Meriwether Lewis (1774–1809) and William Clark (1770-1838) and all their expeditionary men were contemporaries of all those famous British Romanticists, although their world-views and their literary styles were in no way like those of Blake and his friends.


Vignette 7: Some say 'not my problem'

Dateline Waterbury, Connecticut, August 11, 2011

Four fighters were dispatched to an abandoned frame house that was often occupied by transients, and that appeared to be a fire hazard. They were to map a response strategy in the event it should catch fire in the future. It wasn't long before each of the firefighters began to itch, and scratch, and they were driven out of the house by the myriad fleas that had quickly covered their bodies—thousands of them, they declared. Think of it. Their turnout gear could protect them from the heat of a fire up to 500° Fahrenheit, but it was not designed to keep out fleas. On the contrary. . . .

As quickly as they could, they raced to the nearest hospital where, after they stripped down and brushed off all the fleas they could, they were vigorously scrubbed down, and treated for their numerous flea punctures. Meanwhile, their gear was being washed inside and out at a high temperature, and the fire truck was duly fumigated before being returned to service. The four firefighters had to go back to the hospital the next day to be tested for flea-borne infections such as bubonic plague.

Now, whatever became of that flea-infested house?


Vignette 8: A Biological Inclusion in a Drop of Amber

A Fall Upon Hard Times

Small insect in a translucent yellow blob

Photo by George Poinar, Jr. (© 2013) courtesy of Oregon State University

Twenty million years ago. That is when—give or take a few millennia—this particular flea succumbed to the consequences of its own misstep. It somehow fell into a puddle of malleable resin which was exuded from a now extinct tropical tree bearing the generic name Hymenæ (him-men-EYE-uh), and the species epithet protera, "a poker"—a flea—by Carl Linnæus in 1753.9 Subject to the aging processes of oxidation and polymerization over a period of 3–4 million years, the resin became a semi-fossilized substance called copal, and eventually was hardened into the gemstone we call amber.10

This image is especially remarkable for several reasons: First, very few fleas and ticks have been found in amber because they generally cling to their fur-bearing or feathered hosts, which are too large for the average capacity of the medium.11 Second, the biological inclusion is complete enough for an experienced paleo entomologist to identify its species, which in this case is one that went extinct millions of years ago. It was discovered in 1995 by the renowned paleo entomologist George O. Poinar, of Oregon State University, who gave it its one and only formal name, Atoposyllus cionus.12 Third and finally, this is the first specimen of amber found to contain a flea which in turn bears—at the distal end of its mouth parts—droplets of dried bacteria believed to be related to the hideous Black Death microbe, Yersinia pestis.13

The drop of amber that encased this biological inclusion was found in a shallow mine in rocky soil atop a mountain of the Greater Antilles archipelago in the Dominican Republic, which occupies the eastern two-thirds of the island of Hispaniola, between the Gulf of Mexico and the Atlantic Ocean.14

Bear in mind that this flea, dead or alive, was only about 3 mm in length.

  • 1. E. D. Lukashevich and M. B. Mostovski, "Hematophagous [blood-sucking] Insects in the Fossil Record," Paleontological of Journal, vol. 37, no. 2 (2003), 153-161. Translated from the Russian Paleontologicheskii Zhurnal, No. 2 (2003), 48-56. "Fossils of sucking lice and fleas are extremely uncommon," the authors explain on page 153, "which is understandable, since these insects are closely connected with their hosts and, thus, their chance to be successfully buried in deposits of inland water bodies (the main type of fossil insect localities) or in fossil resins is slim."
  • 2. Robert F. Harwood and Maurice T. James, Entomology in Human and Animal Health, 7th ed. (New York: Macmillan, 1979), 319.
  • 3. Bent Sørensen, "Energy use by Eem Neanderthals," Journal of Archaeological Science, Vol. 36, Issue 10 (October 2009), 2203.
  • 4. First Book of Samuel, Chapter 24, verse 15, and Chapter 26, verse 20. New American Bible, St. Joseph Edition, Revised. See also Warren Wiersbe, The Bible Exposition Commentary
  • 5. Aristotle, The History of Animals, (written ca. 350 BCE) translated by D'Arcy Wentworth Thompson. Book V, Part 1. The Internet Classics Archive (c. 350 BCE) http://classics.mit.edu//Aristotle/history_anim.html, (retrieved 6 May 2008).
  • 6. An ancient city on the north coast of Africa a few miles west of Tunis.
  • 7. A homily is "a practical discourse with a view to the spiritual edification of the hearers, rather than for the development of a doctrine or theme." OED.
  • 8. Hope D. Werness, The Continuum Encyclopedia of Animal Symbolism in World Art (London: Continuum International Publishing Group Ltd., 2006), 180.
  • 9. The generic name is a poetic evocation of the Greek god of marriage ceremonies, Hymenaios, whom nature appears to have deliberately symbolized by paired, mirrored leaves connected by short petioles to opposite sides of a stem of a tree-branch. Upon landing, this flea may have been protected from noticeable bodily damage by its tough exoskeleton.
  • 10. George O. Poiner, Life in Amber (Stanford, California: Stanford University Press, 1992), 6.
  • 11. The average weight of raw amber droplets is 1.76–3.5 oz (50–100 grams). The largest natural amber on record was found in 2014 in west Sumatra, a province of Indonesia. It weighs 105 lb (47.6 kg), measures 22.6 x 24.5 x 14.6 in (57.5 x 62 x 37 cm), and is between 15 and 25 my old. Sumatran amber is typically brownish in color and is not transparent; however, it displays a bluish tone when exposed to sunlight or UV rays. It is owned and displayed by the famous jewelers' House of Amber in Copenhagen, Denmark.
  • 12. Both parts were derived from Greek words. The generic name is a combination of atopos, "strange," and posyllo, "flea," (AT-oh-poh-SIL-loh). The specific epithet, expanded from the Greek cion into cionus (SEE-ohn-us), "pillar," refers to the unique shape of a certain exterior organ belonging to a female flea of this species.
  • 13. "Bacteria in ancient flea may be ancestor of the Black Death," News and Research Communications, Oregon State University, Corvallis, Oregon, 28 September 2015.
  • 14. The western third of Hispaniola is occupied by the nation of Haiti.