Male cicadas produce their famously loud calls to attract females, and they do it using one of the most remarkable sound-generating organs in the insect world: a pair of ribbed membranes called tymbals, located on the sides of the abdomen. The noise is not incidental or defensive in its primary purpose. It is a mating advertisement, broadcast at intensities that can exceed 100 decibels in some species. Only males call, and the biology behind how they produce, amplify, and modulate that sound involves specialized muscles, a body cavity that functions like a resonance chamber, and behavioral dynamics that shift with temperature, competition, and female choice.
How the Tymbal Organ Actually Works
The sound starts with a pair of structures called tymbals, stiff cuticular membranes reinforced with ribs, tucked beneath the folded wings on either side of a male cicada’s abdomen. Attached to each tymbal is a muscle that contracts rapidly, pulling the membrane inward. Each contraction buckles the ribs in stages, and each stage of buckling produces a click. When the muscle relaxes, the stiff, spring-loaded ribs snap back into place, producing another click. String those clicks together at speed and you get the characteristic buzzing or pulsing song.
Research on periodical cicadas found that each muscle contraction, occurring at roughly 50 times per second, produces five to six distinct stages of rib buckling per cycle. The recovery between contractions is fast because the tymbal ribs are rich in resilin, a highly elastic protein that stores and releases energy efficiently. The muscles themselves have unusual structural features: their internal filaments are about 30 percent shorter than those found in flight muscles, and their internal scaffolding is arranged in a distinctive perforated lattice that appears to facilitate the rapid, repetitive contractions needed for sustained calling.1PubMed. What the buzz was all about: superfast song muscles rattle the tymbals of male periodical cicadas These are sometimes described as “superfast” muscles, a category shared with only a handful of other biological sound producers, like the vocal muscles of some songbirds and the swim bladder muscles of certain fish.
The result is a system built for endurance. A male cicada can call for hours across the hottest part of the day without the tymbal muscles fatiguing in the way you might expect. The combination of short filaments, elastic rebound, and that perforated lattice structure all contribute to a muscle that can fire thousands of times per minute and keep going.
The Body as an Amplifier
Producing a click by buckling a small membrane would not, on its own, generate the kind of volume cicadas are known for. The amplification comes from the cicada’s own body. The abdominal cavity of a male cicada is largely hollow, and the tympana, thin membranes on the underside of the abdomen, radiate the sound outward. A widely accepted model of cicada acoustics describes this arrangement as functioning like a Helmholtz resonator: the abdominal cavity acts as the resonating chamber, the tympana serve as the sound-radiating surfaces, and the tymbals provide the driving vibration.2The Company of Biologists (J Exp Biol). The scaling of song frequency in cicadas Think of blowing across the top of a bottle. The bottle’s cavity amplifies and shapes a small input of air into a much louder tone. The cicada’s abdomen does something analogous, taking the relatively modest clicks of the tymbal and broadcasting them at startling volume.
This design also means that body size matters for pitch. Larger cicadas tend to have larger abdominal cavities, which resonate at lower frequencies. Smaller species tend to produce higher-pitched calls. The relationship is not perfectly linear, because the stiffness of the tymbals, the number and spacing of ribs, and the tension of the tympana all influence the final frequency. But in broad terms, a bigger cicada is usually a deeper-sounding cicada.
The hollow abdomen that makes males so loud is also why they feel surprisingly light when you pick one up. Females, who do not call, tend to have abdomens packed more densely with reproductive organs. The acoustic hollow is a male-specific anatomical feature, a body plan reshaped around the need to be heard.
What Females Are Actually Listening For
If the entire point of calling is to attract a mate, the question becomes: what makes one male’s call more attractive than another’s? Females are not just responding to the presence of sound. They evaluate specific properties of the call and move preferentially toward males whose songs meet certain criteria.
In at least one well-studied species, females showed a clear preference for males that called at a higher rate with shorter intervals between specific sound elements. Males that produced calls with a shorter gap between tymbal-generated and stridulatory sounds achieved significantly more matings over the breeding season.3PubMed Central. Females prefer males producing a high-rate song with shorter timbal–stridulatory sound intervals in a cicada species The logic, from an evolutionary standpoint, is that producing a faster, more tightly structured call takes more energy and more precise muscular coordination, so it signals a healthier or more vigorous male.
Frequency also matters, though the direction of the preference varies between species. In the cicada Mogannia formosana, phonotaxis experiments showed that females preferred lower-frequency calls, approaching low-frequency sound sources significantly more closely than high-frequency ones.4PubMed. Female preference for song frequency in the cicada Mogannia formosana Matsumura (Hemiptera: Cicadidae) Lower frequency in this context is associated with larger body size, so a female choosing a deeper-voiced male may be choosing a larger, presumably fitter partner. The takeaway is that there is no single “best” cicada call across all species. Each species has its own acoustic signature, and females within that species have preferences tuned to features that reliably indicate quality in their particular ecological context.
This choosiness puts real pressure on males. Calling is not just about being loud enough to be heard. It is about being loud, fast, well-structured, and at the right frequency, all while sustaining the performance long enough to attract a female who may be comparing you to dozens of competitors calling simultaneously.
The Energetic Cost of Being Loud
Cicada calls are among the most energetically expensive behaviors in the insect world. The tymbal muscles fire at extraordinary rates, the performance lasts for extended periods, and the animal is doing all of this in direct sunlight during the hottest hours of the day. Research across acoustic insects has established that female preferences tend to cluster around call features that demand the highest energy expenditure: calling louder, calling longer, and calling at higher rates.5PubMed Central. The best of both worlds: cicada males change costly signals to achieve mates while females choose a mate based on both calling and courtship songs This is not a coincidence. The costliness of the signal is what makes it honest. A male in poor condition cannot fake a sustained, high-rate call any more than an out-of-shape person can fake a marathon finishing time.
For cicadas that spend years underground as nymphs feeding on root sap, the adult stage above ground is brief, sometimes just a few weeks. Males emerge with finite energy reserves, and they have to allocate those reserves between calling, flying to new perching sites, and actual courtship once a female approaches. Spending too much energy on calling before a female arrives means having less for the close-range courtship displays that seal the deal. Some species manage this tradeoff by shifting from a long-range calling song to a distinct, quieter courtship song once a female is nearby, conserving energy at close range while still demonstrating quality through the transition.
Chorus Synchronization and How It Emerges
Anyone who has stood under a tree full of periodical cicadas knows the sound is not a random jumble. It often has a pulsing, rhythmic quality, with large groups of males calling in loose synchrony. This chorus behavior is not centrally coordinated. No lead cicada directs the rhythm. Instead, it emerges from each individual male responding to the sounds around him.
Research on the 17-year periodical cicada Magicicada cassini found that choruses form in trees and cycle regularly, roughly every five seconds. The degree of synchrony across a group depends on how strongly the cicadas can hear each other: when audio interactions between individuals are stronger, spatial synchrony increases. The study also found that canopy light levels play a significant role. Brighter conditions increase individual calling activity, which leads to faster chorus cycling, higher amplitude, and tighter synchronization. A relaxation-oscillator model, essentially treating each cicada as a simple unit that resets its timing based on what it hears, reproduced these patterns well.6PubMed Central. Self-organizing cicada choruses respond to the local sound and light environment
The practical implication is that a cicada chorus is a self-organizing system. Each male adjusts his timing slightly in response to his neighbors, and the aggregate result is a wave of sound that pulses through a tree or a patch of forest. The synchrony is never perfect; it is a statistical tendency, not a lockstep march. But it is striking enough that researchers have used cicada choruses as a model system for studying self-organization in biology more broadly.
Within these choruses, individual males also have to contend with direct competition. When two males are calling in close proximity, they sometimes produce distinct call types that appear timed relative to the competitor’s signals. One hypothesis was that males deliberately overlap their rival’s calls to jam or mask them, but an analysis of 23 competing males found that this overlap was not statistically better than random for most individuals.7Journal of Experimental Biology. Temporal structure of two call types produced by competing male cicadas Males are clearly adjusting their behavior in the presence of competitors, but the strategy does not seem to be sophisticated signal jamming. It may be more about standing out through intensity or timing shifts rather than actively silencing a rival.
Why Temperature Changes What You Hear
If you have noticed that cicada calls sound different at different times of day, or that the buzzing seems to pick up as the afternoon heats up, you are hearing the direct effect of temperature on muscle physiology. Cicada tymbal muscles, like all insect muscles, are strongly influenced by ambient and body temperature. As temperature rises, muscle contractions become faster and stronger, which changes the temporal structure of the call.
In the bladder cicada Cystosoma saundersii, rising temperature produces faster tymbal contractions and notably shorter intervals between sound pulses within a single tymbal buckling event, along with somewhat shorter intervals between successive bucklings.8Journal of Experimental Biology. Body Temperature and Singing in the Bladder Cicada, Cystosoma Saundersii The song gets faster and more compressed as the insect warms up. A study of three Portuguese cicada species found the same pattern: syllable rates and the rate at which song phrases repeated both showed strong temperature dependence across a range of roughly 24 to 38 degrees Celsius.9PubMed. Temperature dependence of cicada songs (Homoptera, Cicadoidea)
The relationship is not always straightforward. In one of those Portuguese species, Tettigetta argentata, the rate at which song phrases repeated increased with temperature up to about 33 degrees but then decreased at the highest temperatures tested. This suggests that the neural circuits controlling different aspects of the song do not all respond to temperature in the same way. At least in some species, two or more separate neural networks govern different timing parameters of the call, and those networks have different thermal sensitivities.9PubMed. Temperature dependence of cicada songs (Homoptera, Cicadoidea)
This has a practical consequence for the cicadas themselves. Since females evaluate temporal properties of the call when choosing a mate, a male’s apparent quality shifts with temperature. A cooler male sounds slower. A warmer male sounds faster and more vigorous. Some cicadas actively thermoregulate by basking in sunlight or adjusting their body posture to absorb heat, which is not just about comfort; it directly affects how attractive their song sounds. The connection between sunlight, canopy openness, chorus intensity, and mating success all converge here: warmer, brighter conditions produce louder, faster, more synchronized calling, which is exactly what females prefer.
The Danger of Being Heard
There is an obvious downside to broadcasting your location at extreme volume: predators can hear you too. Cicadas are eaten by birds, wasps, spiders, squirrels, and a wide range of other animals. The question of whether the sheer noise of a cicada chorus deters predators or simply attracts them has been studied most directly in the context of periodical cicada emergences and bird predation.
Research on red-winged blackbirds preying on periodical cicadas found that the loud noise produced by males at mating aggregation sites did not appear to deter predation.10PubMed. Red-winged blackbird predation on periodical cicadas (Cicadidae: Magicicada spp.): bird behavior and cicada responses Birds fed on cicadas at calling centers without apparent hesitation. The primary defense of periodical cicadas against predation is not acoustic deterrence but predator satiation: by emerging in the billions over a few weeks, the cicadas ensure that predators cannot eat enough of them to significantly dent the population. A bird can only eat so many cicadas in a day, and there are always more.
For annual cicada species that do not emerge in such overwhelming numbers, the tradeoff between calling loudly and being eaten is more acute. These species tend to call from elevated perches in trees, where they are harder for ground-based predators to reach, and many will go silent if they detect movement nearby. The abrupt silence of a cicada when you walk under its tree is a predator-avoidance behavior, not shyness. Some species also produce a distinct alarm or protest call when grabbed, a harsh, erratic burst of sound quite different from the mating call. Whether this startles the predator into releasing its grip or simply signals distress is not entirely settled, but it is clearly a different acoustic behavior from the rhythmic calling song.
Why Only Males Call
In most cicada species, sound production is exclusively male. Females lack functional tymbals and the hollow abdominal resonating cavity. They respond to male calls, but not by calling back at comparable volume. Instead, a receptive female typically signals her interest by flicking her wings, producing a brief click that the nearby male can hear. This wing-flick response is much quieter than the male’s call, audible only at close range, which makes sense: by the time a female is responding, the male is usually already nearby. There is no need for her to broadcast across a forest.
This division of labor, males call loudly and females respond quietly, is common across acoustic insects, but the degree to which cicadas have committed to it is extreme. The entire male body plan is shaped around sound production. The hollow abdomen, the superfast muscles, the resonating tympana: these are not minor modifications. They represent a substantial reallocation of body resources away from other functions and toward acoustic signaling. It is a level of anatomical specialization that reflects millions of years of sexual selection pressure, where the males that were loudest, fastest, and most persistent left the most offspring.
There are a handful of cicada species in which females produce sounds that go beyond a simple wing flick, but these are exceptions. The overwhelming pattern across the roughly 3,000 described cicada species is a noisy male and a quiet female, with the female exercising choice by moving toward the call she finds most appealing and signaling acceptance only when she is close enough that a whisper will do.
Annual Versus Periodical Cicada Calls
The cicadas most people encounter each summer are annual species, sometimes called “dog-day” cicadas, which emerge every year in overlapping generations. Their calls are the sustained, high-pitched buzzing or whining that forms the background soundtrack of a warm afternoon. Periodical cicadas, the ones that emerge in massive synchronized broods every 13 or 17 years, produce calls that sound quite different: more pulsing, more rhythmic, and often delivered in the synchronized chorus patterns described earlier.
The differences are partly a function of species-specific tymbal anatomy and muscle-firing rates, but they also reflect different ecological strategies. Annual cicadas are relatively solitary callers. A male in a tree is trying to attract a female largely on his own, competing with other males but not participating in the kind of large-scale coordinated display that periodical cicadas produce. Periodical cicadas, by contrast, form dense aggregations where the chorus itself becomes part of the signal. The wall of synchronized sound may help females locate the aggregation from a distance, even if picking out individual males within it requires closer inspection.
The sheer volume of a periodical cicada emergence is something that has to be experienced to be appreciated. Researchers have measured sustained sound levels above 90 decibels inside active choruses, which is comparable to standing next to a lawnmower. The noise can be physically uncomfortable for people spending extended time in affected areas, and some entomologists working in emergence zones wear hearing protection. For the cicadas, though, that extreme volume is the entire point: the culmination of years underground, a few weeks of furious calling, and then silence until the next generation emerges more than a decade later.