Moth Facts: 160,000 Species, Sonar Jamming, Star Maps

• Moths outnumber butterflies roughly nine to one. About 160,000 known moth species worldwide against some 17,500 butterflies, with nearly 11,000 moth species in the United States. In Britain the ratio is starker still: over 2,500 moth species to fewer than 70 butterflies, of which around 900 are 'macro-moths' and the rest micros.
• The atlas moth's wingspan is routinely exaggerated. The Natural History Museum gives up to 27 cm — wider than a human handspan — and the caterpillars reach 12 cm. The 12-inch (30 cm) figure that circulates online is not what museums report; Washington State's agriculture department describes the moth as 'up to almost 10 inches', about 25 cm. The real number sits in the mid-to-high 20s of centimetres, and it is the wing area rather than the span that makes atlas moths look enormous.
• Adult atlas moths cannot eat. The proboscis is tiny and does not work, so they live one to two weeks on fat reserves laid down as caterpillars, then run out of the energy needed to power their wings.
• Their cocoons are used as purses. Atlas moth caterpillars secrete a coarse brown broken-stranded silk called fagara, and in some Asian countries the abandoned cocoons are durable enough to be repurposed.
• Its Cantonese name translates as 'snake's head moth'. The wingtips resemble a cobra's head, and a threatened moth drops to the ground and writhes, flapping slowly to imitate a snake's head and neck.
• The largest-moth record is shakier than it looks. The white witch (Thysania agrippina) of South America is credited with the longest reported span of any lepidopteran, up to 280 mm, though the only specimens actually measured came in at 260 mm and 266 mm. On wing area rather than span, several southern Asian saturniids surpass it.
• Luna moth tails are anti-bat decoys. In laboratory trials against big brown bats, tailed luna moths had roughly a 47% survival advantage over moths whose tails had been removed, and bats struck the spinning tails instead of the body in 55% of encounters.
• One tiger moth jams bat sonar. Bertholdia trigona is palatable, so its ultrasonic clicks cannot be an honest toxicity warning — ultrasonic recordings and high-speed infrared video show they jam the bat's sonar instead. Other tiger moths do use clicks aposematically or to startle; jamming adds to that repertoire rather than replacing it.
• Moth wings are an acoustic stealth coating. The scale layer works as a metamaterial ultrasound absorber, soaking up 72% of sound intensity at 78 kHz in a layer 111 times thinner than the longest wavelength it absorbs.
• Bogong moths read the starry sky as a compass. Tethered in a flight simulator under a naturalistic moonless sky with the geomagnetic field nulled, they still flew in their seasonally correct migratory direction — evidence that stars alone suffice, though the authors conclude the moths combine stellar and magnetic cues into one compass system. The migration runs up to 1,000 km, to alpine caves the individual moth has never visited.
• The greater wax moth hears higher than any other known animal. It senses frequencies up to 300 kHz, the highest recorded frequency sensitivity in nature. Humans manage about 20 kHz; dolphins stop near 160 kHz.
• Moths deposit pollen faster than daytime insects. Across 10 South East England sites, 83% of insect visits to bramble happened in daylight and moths made only 15% of visits, yet moths deposited pollen at a faster rate — the researchers' conclusion is that moths are the more efficient pollinators, not that they contribute more pollination overall, which the study did not report.
• The peppered moth's black form came from a jumping gene. The textbook example of evolution in action traces to a transposable element that inserted itself into the first intron of a gene called cortex. Statistical inference from recombined haplotypes dates the event to around 1819, at the height of the Industrial Revolution.
• Wallace's sphinx moth has the longest tongue of any insect. Across roughly 130 Xanthopan specimens from Africa, the Comoros and Madagascar, proboscises measured 15 to 28.5 cm, with the record a Madagascan male. They were too long to store extended in the museum's existing drawers.
• The death's-head hawkmoth squeaks by pumping air through its throat. Each squeak lasts about 200 milliseconds and consists of an inflation phase, a short pause and a deflation phase. The inflation burst carries around 50 pulses peaking near 8 kHz, with harmonics running past 60 kHz.
• Vampire moths drink blood, with caveats. Moths in the genus Calyptra pierce mammal skin with a barbed proboscis, human skin included. It is the males that do it, and only in some species; females feed on fruit juice and nectar, larvae eat leaves, the single North American Calyptra species is not a known blood-feeder, and none is known to transmit disease.
• North America's spongy moth invasion started in one backyard. The amateur entomologist Étienne Léopold Trouvelot reared larvae from imported egg masses in cages on trees behind his home in Medford, Massachusetts. They escaped in 1868 or 1869, and no control was attempted until 1890.
• Britain's larger moths are in steep decline. The abundance of Britain's larger (macro-)moths has fallen 28% since 1968, and 40% in southern Britain. Butterfly Conservation counts 51 British moth extinctions since 1900, with some species since recolonising or being re-found.

"Moths fly into your porch light because they mistake it for the moon and their lunar navigation goes haywire." They are not flying toward the light at all. In 2024, high-speed motion capture and field stereo-videography showed that insects tilt their backs toward the brightest thing they can see — a reflex that normally keeps them upright under an open sky. Near a bulb, that reflex locks them into a perpendicular orbit around it. Nobody is aiming at anything, and no lunar compass is being fooled.

"Moths eat your clothes." Adult clothes moths have no working mouthparts and do no damage whatsoever, so the fluttering thing in your wardrobe is not the culprit, it is the parent. The larvae do the chewing, and only on keratin: wool, fur, silk, feathers, felt, leather. Cotton and synthetics are safe unless blended or food-stained. Of Britain's 2,500-plus moth species, only a handful touch fabric at all.

"You can always tell a moth from a butterfly: butterflies have clubbed antennae, moths have feathery or threadlike ones." Day-flying burnet moths have club-like antennae, and the popular rules do not hold. Both groups sit in the same order, Lepidoptera, and there is no clean dividing line between them.

The moth's assigned cultural role is to be drawn to a flame, and the image has survived mainly because nobody tested it. When researchers finally did, using high-speed motion capture in the laboratory and stereo-videography in the field, the result was published in Nature Communications in 2024 and read as a flat contradiction: insects do not steer toward the light. They turn their dorsum toward it, which is a reflex for keeping the back to the open sky, and near a point source that reflex produces flight bouts perpendicular to the bulb. The moth circling your porch is not chasing anything. It is trapped in a postural correction that has nothing left to correct against.

The second stock role is the horror prop, and here the animals cooperate more readily. The USDA's Agricultural Research Service runs its own Halloween billing for the blood-drinking moths of the genus Calyptra, which pierce skin with a barbed proboscis — though the agency is careful to note that it is the males doing it, that females stick to fruit, and that no disease transmission is known. The death's-head hawkmoth earns its billing acoustically rather than visually, forcing air in and out of its throat to produce a 200-millisecond squeak of about 50 pulses, peaking near 8 kHz with harmonics past 60 kHz. The atlas moth does the most theatrical impression of all: its Cantonese name translates as snake's head moth, its wingtips resemble a cobra's head, and a threatened individual drops to the ground and writhes, flapping slowly to sell the illusion. Its cocoons, spun from a coarse brown silk called fagara, end up as purses in parts of Asia — the same animal serving as monster and as haberdashery.

The peppered moth is the moth almost everyone has met, usually in a school textbook as the standard demonstration of natural selection under industrial soot. The molecular explanation arrived in 2016: the black form was produced by a transposable element — a jumping gene — inserting itself into the first intron of a gene called cortex. Statistical inference from the distribution of recombined carbonaria haplotypes dates that insertion to around 1819, which fits the historical record of the Industrial Revolution.

Wallace's sphinx moth was famous before it was a species of its own. Predicted to exist by Darwin and Wallace, the Madagascan population was described as Xanthopan praedicta in 2021. Measurements across roughly 130 Xanthopan specimens from Africa, the Comoros and Madagascar returned proboscises of 15 to 28.5 cm, the longest of any insect, the record held by a Madagascan male — and too long to store extended in the museum's drawers, so the researchers rolled them back in by returning each head to water.

Australia's Bogong moth made Nature in 2025 for navigation rather than size. It migrates up to 1,000 km across southeast Australia to alpine caves it has never previously visited, and tethered flight-simulator experiments under a naturalistic moonless sky, with the geomagnetic field nulled, showed it still held its inherited migratory direction. Stars alone are sufficient, though the authors conclude the moths combine stellar and magnetic cues into a single compass system.

Two more are famous inside their own field. Bertholdia trigona, a palatable tiger moth with no honest toxicity to advertise, was shown in 2009 to jam big brown bat sonar with ultrasonic clicks. The luna moth's long spinning hindwing tails were shown in 2015 to be acoustic decoys, giving tailed moths roughly a 47% survival advantage against the same bat species, with strikes landing on the tails in 55% of encounters. And the spongy moth is famous for the worst reason: Étienne Léopold Trouvelot reared imported larvae in his Medford, Massachusetts backyard, they escaped in 1868 or 1869, and nobody attempted control until 1890.