sound
In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid.
In human physiology and psychology, sound is the ''reception'' of such waves and their ''perception'' by the ...
by rubbing together certain body parts. This behavior is mostly associated with
insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...
s, but other animals are known to do this as well, such as a number of species of
fish
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...
,
snake
Snakes are elongated, Limbless vertebrate, limbless, carnivore, carnivorous reptiles of the suborder Serpentes . Like all other Squamata, squamates, snakes are ectothermic, amniote vertebrates covered in overlapping Scale (zoology), scales. Ma ...
s and
spider
Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...
s. The mechanism is typically that of one structure with a well-defined lip, ridge, or nodules (the "scraper" or ''plectrum'') being moved across a finely-ridged surface (the "file" or ''stridulitrum''—sometimes called the ''pars stridens'') or vice versa, and vibrating as it does so, like the dragging of a
phonograph
A phonograph, in its later forms also called a gramophone (as a trademark since 1887, as a generic name in the UK since 1910) or since the 1940s called a record player, or more recently a turntable, is a device for the mechanical and analogu ...
needle across a
vinyl record
A phonograph record (also known as a gramophone record, especially in British English), or simply a record, is an analog sound storage medium in the form of a flat disc with an inscribed, modulated spiral groove. The groove usually starts nea ...
. Sometimes it is the structure bearing the file which resonates to produce the sound, but in other cases it is the structure bearing the scraper, with both variants possible in related groups. Common
onomatopoeic
Onomatopoeia is the process of creating a word that phonetically imitates, resembles, or suggests the sound that it describes. Such a word itself is also called an onomatopoeia. Common onomatopoeias include animal noises such as ''oink'', ''m ...
words for the sounds produced by stridulation include ''chirp'' and ''chirrup''.
Arthropod stridulation
Insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...
s and other
arthropod
Arthropods (, (gen. ποδός)) are invertebrate animals with an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arth ...
s stridulate by rubbing together two parts of the body. These are referred to generically as the ''stridulatory organs''.
The mechanism is best known in
cricket
Cricket is a bat-and-ball game played between two teams of eleven players on a field at the centre of which is a pitch with a wicket at each end, each comprising two bails balanced on three stumps. The batting side scores runs by striki ...
s,
mole cricket
Mole crickets are members of the insect family Gryllotalpidae, in the order Orthoptera (grasshoppers, locusts, and crickets). Mole crickets are cylindrical-bodied, fossorial insects about long as adults, with small eyes and shovel-like fore ...
s, and
grasshopper
Grasshoppers are a group of insects belonging to the suborder Caelifera. They are among what is possibly the most ancient living group of chewing herbivorous insects, dating back to the early Triassic around 250 million years ago.
Grasshopp ...
s, but other insects which stridulate include
Curculionidae
The Curculionidae are a family of weevils, commonly called snout beetles or true weevils. They are one of the largest animal families, with 6,800 genera and 83,000 species described worldwide. They are the sister group to the family Brentidae.
T ...
(weevils and bark beetles),
Cerambycidae
The longhorn beetles (Cerambycidae), also known as long-horned or longicorns, are a large family of beetles, with over 35,000 species described. Most species are characterized by extremely long antennae, which are often as long as or longer than ...
(longhorned beetles),
Mutillidae
The Mutillidae are a family of more than 7,000 species of wasps whose wingless females resemble large, hairy ants. Their common name velvet ant refers to their dense pile of hair, which most often is bright scarlet or orange, but may also be bla ...
("velvet ants"),
Reduviidae
The Reduviidae are a large cosmopolitan family of the order Hemiptera (true bugs). Among the Hemiptera and together with the Nabidae almost all species are terrestrial ambush predators: most other predatory Hemiptera are aquatic. The main exampl ...
(assassin bugs),
Buprestidae
Buprestidae is a family of beetles known as jewel beetles or metallic wood-boring beetles because of their glossy iridescent colors. Larvae of this family are known as flatheaded borers. The family is among the largest of the beetles, with some ...
(metallic wood-boring beetles),
Hydrophilidae
Hydrophilidae, also known colloquially as water scavenger beetles, is a family of beetles. Aquatic hydrophilids are notable for their long maxillary palps, which are longer than their antennae. Several of the former subfamilies of Hydrophilidae ...
(water scavenger beetles),
Cicindelinae
Tiger beetles are a family of beetles, Cicindelidae, known for their aggressive predatory habits and running speed. The fastest known species of tiger beetle, ''Rivacindela hudsoni'', can run at a speed of , or about 125 body lengths per second. ...
(tiger beetles),
Scarabaeidae
The family Scarabaeidae, as currently defined, consists of over 30,000 species of beetles worldwide; they are often called scarabs or scarab beetles. The classification of this family has undergone significant change in recent years. Several sub ...
(scarab beetles),
Glaresidae
''Glaresis'' is a genus of beetles, sometimes called "Enigmatic scarab beetles", in its own family, the Glaresidae. It is closely related to, and was formerly included in, the family Scarabaeidae. Although its members occur in arid and sandy area ...
("enigmatic scarabs"),
larva
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle.
The ...
l
Lucanidae
Stag beetles are a family of about 1,200 species of beetles in the family Lucanidae, currently classified in four subfamilies.Smith, A.B.T. (2006). A review of the family-group names for the superfamily Scarabaeoidea (Coleoptera) with corrections ...
(stag beetles),
Passalidae
Passalidae is a family of beetles known variously as "bessbugs", "bess beetles", "betsy beetles" or "horned passalus beetles". Nearly all of the 500-odd species are tropical; species found in North America are notable for their size, ranging fro ...
(Bessbugs),
Geotrupidae
Geotrupidae (from Greek γῆ ''(gē)'', earth, and τρῡπητής ''(trȳpētēs)'', borer) is a family of beetles in the order Coleoptera. They are commonly called earth-boring dung beetles or dor beetles. Most excavate burrows in which ...
(earth-boring dung beetles),
Alydidae
Alydidae, commonly known as broad-headed bugs, is a family of true bugs very similar to the closely related Coreidae (leaf-footed bugs and relatives). There are at least 60 genera and 300 species altogether. Distributed in the temperate and war ...
(broad-headed bugs),
Largidae
Largidae is a family of insects within the order Hemiptera. They are commonly known as bordered plant bugs because many have contrasting coloured edges to their hemelytra. There are fifteen genera and about one hundred species. They are mostly w ...
(bordered plant bugs),
Miridae
The Miridae are a large and diverse insect family at one time known by the taxonomic synonym Capsidae. Species in the family may be referred to as capsid bugs or "mirid bugs". Common names include plant bugs, leaf bugs, and grass bugs. It is the ...
(leaf bugs),
Corixidae
Corixidae is a family of aquatic insects in the order Hemiptera. They are found worldwide in virtually any freshwater habitat and a few species live in saline water. There are about 500 known species worldwide, in 55 genera, including the genus ' ...
(water boatmen, notably ''
Micronecta scholtzi
''Micronecta scholtzi'', the lesser water boatman, is a species of pygmy water boatman in the family Micronectidae. It was first described by Franz Xaver Fieber in 1860. They are some 2 mm long and are common in freshwater ponds and lakes ...
''), various
ant
Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22 ...
stick insects
The Phasmatodea (also known as Phasmida, Phasmatoptera or Spectra) are an order of insects whose members are variously known as stick insects, stick-bugs, walking sticks, stick animals, or bug sticks. They are also occasionally referred to as ...
Agromyzidae
The Agromyzidae are a family commonly referred to as the leaf-miner flies, for the feeding habits of their larvae, most of which are leaf miners on various plants.
A worldwide family of roughly 2,500 species, they are small, some with wing leng ...
(leaf-mining flies). While
cicada
The cicadas () are a superfamily, the Cicadoidea, of insects in the order Hemiptera (true bugs). They are in the suborder Auchenorrhyncha, along with smaller jumping bugs such as leafhoppers and froghoppers. The superfamily is divided into two ...
s are well-known for sound production via abdominal
tymbal
The tymbal (or timbal) is the corrugated exoskeletal structure used to produce sounds in insects. In male cicadas, the tymbals are membranes in the abdomen, responsible for the characteristic sound produced by the insect. In tiger moths, the t ...
organs, it has been demonstrated that some species can produce sounds via stridulation, as well.
Stridulation is also known in a few
tarantula
Tarantulas comprise a group of large and often hairy spiders of the family Theraphosidae. , 1,040 species have been identified, with 156 genera. The term "tarantula" is usually used to describe members of the family Theraphosidae, although ...
s (Arachnida), and some
pill millipede
Pill millipedes are any members of two living (and one extinct) orders of millipedes, often grouped together into a single superorder, Oniscomorpha. The name Oniscomorpha refers to the millipedes' resemblance to certain woodlice (Oniscidea), also ...
s (Diplopoda, Oniscomorpha).
It is also widespread among decapod crustaceans, e.g., rock lobsters. Most spiders are silent, but some tarantula species are known to stridulate. When disturbed, ''
Theraphosa blondi
The Goliath birdeater (''Theraphosa blondi'') belongs to the tarantula family Theraphosidae. Found in northern South America, it is the largest spider in the world by mass () and body length (up to ), and second to the giant huntsman spider by ...
'', the Goliath tarantula, can produce a rather loud hissing noise by rubbing together the bristles on its legs. This is said to be audible to a distance of up to 15 feet (4.5 m).Goliath Tarantula, ''Theraphosa blondi'' a Extreme Science . Accessed 13 March 2007. One of the
wolf spider
Wolf spiders are members of the family Lycosidae (). They are robust and agile hunters with excellent eyesight. They live mostly in solitude, hunt alone, and do not spin webs. Some are opportunistic hunters, pouncing upon prey as they find it or ...
s, '' Schizocosa stridulans'', produces low-frequency sounds by flexing its abdomen (tremulation, rather than stridulation) or high-frequency stridulation by using the cymbia on the ends of its
pedipalps
Pedipalps (commonly shortened to palps or palpi) are the second pair of appendages of chelicerates – a group of arthropods including spiders, scorpions, horseshoe crabs, and sea spiders. The pedipalps are lateral to the chelicerae ("jaws") and ...
. In most species of spiders, stridulation commonly occurs by males during sexual encounters. In the species '' Holocnemus pluchei'', females also possess stridulatory organs, and both sexes engage in stridulation. In the species '' Steatoda nobilis,'' the males produce stridulation sounds during mating.
The anatomical parts used to produce sound are quite varied: the most common system is that seen in grasshoppers and many other insects, where a hind leg scraper is rubbed against the adjacent forewing (in
beetle
Beetles are insects that form the order Coleoptera (), in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 400,000 describ ...
s and
true bug
Hemiptera (; ) is an order of insects, commonly called true bugs, comprising over 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from to around ...
s the forewings are hardened); in crickets and
katydid
Insects in the family Tettigoniidae are commonly called katydids (especially in North America), or bush crickets. They have previously been known as "long-horned grasshoppers". More than 8,000 species are known. Part of the suborder Ensifera, t ...
s a file on one wing is rubbed by a scraper on the other wing; in longhorned beetles, the back edge of the
pronotum
The prothorax is the foremost of the three segments in the thorax of an insect, and bears the first pair of legs. Its principal sclerites (exoskeletal plates) are the pronotum (dorsal), the prosternum (ventral), and the propleuron (lateral) on ea ...
scrapes against a file on the
mesonotum
The mesothorax is the middle of the three segments of the thorax of hexapods, and bears the second pair of legs. Its principal sclerites (exoskeletal plates) are the mesonotum (dorsal), the mesosternum (ventral), and the mesopleuron (lateral) on ...
; in various other beetles, the sound is produced by moving the head—up/down or side-to-side—while in others the abdominal
tergite
A ''tergum'' (Latin for "the back"; plural ''terga'', associated adjective tergal) is the dorsal ('upper') portion of an arthropod segment other than the head. The anterior edge is called the 'base' and posterior edge is called the 'apex' or 'mar ...
s are rubbed against the
elytra
An elytron (; ; , ) is a modified, hardened forewing of beetles (Coleoptera), though a few of the true bugs (Hemiptera) such as the family Schizopteridae are extremely similar; in true bugs, the forewings are called hemelytra (sometimes alterna ...
; in assassin bugs, the tip of the mouthparts scrapes along a ridged groove in the
prosternum
The prothorax is the foremost of the three segments in the thorax of an insect, and bears the first pair of legs. Its principal sclerites (exoskeletal plates) are the pronotum (dorsal), the prosternum (ventral), and the propleuron (lateral) on ea ...
; in velvet ants the back edge of one abdominal tergite scrapes a file on the dorsal surface of the following tergite.
Stridulation in several of these examples is for attracting a mate, or as a form of
territorial behaviour
In ethology, territory is the sociographical area that an animal consistently defends against conspecific competition (or, occasionally, against animals of other species) using agonistic behaviors or (less commonly) real physical aggression. A ...
, but can also be a warning signal (acoustic
aposematism
Aposematism is the advertising by an animal to potential predators that it is not worth attacking or eating. This unprofitability may consist of any defences which make the prey difficult to kill and eat, such as toxicity, venom, foul taste or ...
, as in velvet ants and tarantulas). This kind of communication was first described by Slovenian biologist
Ivan Regen
Ivan (or Janez) Regen (known also as Johann Regen) (December 9, 1868 – July 27, 1947) was a Slovenian biologist, best known for his studies in the field of bioacoustics.
Regen was born in the hamlet of Lajše in Trata (today part of Gorenja Va ...
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of
venomous snake
Venomous snakes are Species (biology), species of the Suborder (biology), suborder Snake, Serpentes that are capable of producing Snake venom, venom, which they use for killing prey, for defense, and to assist with digestion of their prey. The v ...
s stridulate as part of a threat display. They arrange their body into a series of parallel C-shaped (counterlooped) coils that they rub together to produce a sizzling sound, rather like water on a hot plate. The best-known examples are members of the
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
''
Echis
''Echis'' (common names: saw-scaled vipers, carpet vipersSpawls S, Branch B. 1995. ''The Dangerous Snakes of Africa''. Dubai: Ralph Curtis Books. Oriental Press. 192 pp. .) is a genus of vipers found in the dry regions of Africa, the Middle E ...
'' (saw-scaled vipers), although those of the genus ''
Cerastes
The cerastes (Greek: κεράστης, transliteration: ''kerastēs'', meaning "having horns"Atheris desaixi'', do this as well.Spawls S, Branch B. 1995. The Dangerous Snakes of Africa. Ralph Curtis Books. Dubai: Oriental Press. 192 pp. .Mallow D, Ludwig D, Nilson G. 2003. True Vipers: Natural History and Toxinology of Old World Vipers. Krieger Publishing Company, Malabar, Florida. 359 pp. . A
bird
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
, the
club-winged manakin
The club-winged manakin (''Machaeropterus deliciosus'') is a small passerine bird which is a resident breeding species in the cloud forest on the western slopes of the Andes Mountains of Colombia and northwestern Ecuador. The manakins are a famil ...
, has a dedicated stridulation apparatus, while a species of mammal, the lowland streaked tenrec, (''Hemicentetes semispinosus'') produces a high-pitched noise by rubbing together specialised quills on its back.