Temporal range: 396–0  Ma
Early Devonian [1] (but see text) – Present
Insect collage.png
Clockwise from top left: dance fly ( Empis livida), long-nosed weevil ( Rhinotia hemistictus), mole cricket ( Gryllotalpa brachyptera), German wasp (Vespula germanica), emperor gum moth ( Opodiphthera eucalypti), assassin bug ( Harpactorinae)
A chorus of several Magicicada species
Scientific classification e
Kingdom: Animalia
Clade: Euarthropoda
Clade: Pancrustacea
Subphylum: Hexapoda
Class: Insecta
Linnaeus, 1758

See text.

  • Ectognatha
  • Entomida

Insects or Insecta (from Latin insectum) are by far the largest group of hexapod invertebrates within the arthropod phylum. Definitions and circumscriptions vary; usually, insects comprise a class within the Phylum Arthropoda. As used here, the term is synonymous with Ectognatha. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs of jointed legs, compound eyes and one pair of antennae. The most diverse group of animals, they include more than a million described species and represent more than half of all known living organisms. [2] [3] The number of extant species is estimated at between six and ten million, [2] [4] [5] and potentially represent over 90% of the animal life forms on Earth. [6] Insects may be found in nearly all environments, although only a small number of species reside in the oceans, a habitat dominated by another arthropod group, crustaceans.

The life cycles of insects vary but most hatch from eggs. Insect growth is constrained by the inelastic exoskeleton and development involves a series of molts. The immature stages can differ from the adults in structure, habit and habitat, and can include a passive pupal stage in those groups that undergo four-stage metamorphosis (see holometabolism). Insects that undergo three-stage metamorphosis lack a pupal stage and adults develop through a series of nymphal stages. [7] The higher level relationship of the Hexapoda is unclear. Fossilized insects of enormous size have been found from the Paleozoic Era, including giant dragonflies with wingspans of 55 to 70 cm (22–28 in). The most diverse insect groups appear to have coevolved with flowering plants.

Adult insects typically move about by walking, flying, or sometimes swimming. As it allows for rapid yet stable movement, many insects adopt a tripedal gait in which they walk with their legs touching the ground in alternating triangles. Insects are the only invertebrates to have evolved flight. Many insects spend at least part of their lives under water, with larval adaptations that include gills, and some adult insects are aquatic and have adaptations for swimming. Some species, such as water striders, are capable of walking on the surface of water. Insects are mostly solitary, but some, such as certain bees, ants and termites, are social and live in large, well-organized colonies. Some insects, such as earwigs, show maternal care, guarding their eggs and young. Insects can communicate with each other in a variety of ways. Male moths can sense the pheromones of female moths over great distances. Other species communicate with sounds: crickets stridulate, or rub their wings together, to attract a mate and repel other males. Lampyridae in the beetle order communicate with light.

Humans regard certain insects as pests, and attempt to control them using insecticides and a host of other techniques. Some insects damage crops by feeding on sap, leaves, fruits, or, in the case of termites, the wood itself. A few parasitic species are pathogenic. Some insects perform complex ecological roles; blow-flies, for example, help consume carrion but also spread diseases. Insect pollinators are essential to the life cycle of many flowering plant species on which most organisms, including humans, are at least partly dependent; without them, the terrestrial portion of the biosphere (including humans) would be devastated. [8] Many other insects are considered ecologically beneficial as predators and a few provide direct economic benefit. Silkworms and bees have been used extensively by humans for the production of silk and honey, respectively. In some cultures, people eat the larvae or adults of certain insects.


The word "insect" comes from the Latin word insectum, meaning "with a notched or divided body", or literally "cut into", from the neuter singular perfect passive participle of insectare, "to cut into, to cut up", from in- "into" and secare "to cut"; [9] because insects appear "cut into" three sections. A calque of Greek ἔντομον [éntomon], "cut into sections", Pliny the Elder introduced the Latin designation as a loan-translation of the Greek word ἔντομος (éntomos) or "insect" (as in entomology), which was Aristotle's term for this class of life, also in reference to their "notched" bodies. "Insect" first appears documented in English in 1601 in Holland's translation of Pliny. Translations of Aristotle's term also form the usual word for "insect" in Welsh ( trychfil, from trychu "to cut" and mil, "animal"), Serbo-Croatian (zareznik, from rezati, "to cut"), Russian ( насекомое nasekomoje, from seč'/-sekat', "to cut"), etc. [9] [10]

Other Languages
Адыгэбзэ: ХьэпӀацӀэхэр
Afrikaans: Insek
Alemannisch: Insekten
አማርኛ: ሦስት አጽቄ
Ænglisc: Ceorfdēor
العربية: حشرة
aragonés: Insecta
ܐܪܡܝܐ: ܪܚܫܐ
armãneashti: Insectâ
অসমীয়া: পতংগ
asturianu: Inseutu
Avañe'ẽ: Tymbachu'i
Aymar aru: Ch'iwi
azərbaycanca: Həşəratlar
تۆرکجه: حشراتلار
বাংলা: কীট
Bân-lâm-gú: Khun-thiông
Basa Banyumasan: Srangga
башҡортса: Бөжәктәр
беларуская: Насякомыя
беларуская (тарашкевіца)‎: Вусякі
Bislama: Insek
български: Насекоми
bosanski: Insekti
brezhoneg: Amprevan
català: Insectes
Cebuano: Insekto
čeština: Hmyz
Cymraeg: Pryf
dansk: Insekter
Deutsch: Insekten
eesti: Putukad
Ελληνικά: Έντομα
español: Insecta
Esperanto: Insektoj
estremeñu: Insecta
euskara: Intsektu
فارسی: حشره
Fiji Hindi: Kirwa
føroyskt: Skordýr
français: Insecte
Frysk: Ynsekten
Gaeilge: Feithid
Gaelg: Insecta
galego: Insectos
𐌲𐌿𐍄𐌹𐍃𐌺: 𐌰𐌹𐌽𐍄𐍉𐌼𐍉𐌽
客家語/Hak-kâ-ngî: Khûn-chhùng
хальмг: Хорха
한국어: 곤충
Հայերեն: Միջատներ
हिन्दी: कीट
hrvatski: Kukci
Ido: Insekto
Ilokano: Insekto
Bahasa Indonesia: Serangga
interlingua: Insecta
íslenska: Skordýr
italiano: Insecta
עברית: חרקים
ಕನ್ನಡ: ಕೀಟ
Kapampangan: Insectu
ქართული: მწერები
कॉशुर / کٲشُر: کیوٚم
қазақша: Жәндіктер
kernowek: Hweskeren
Kinyarwanda: Inigwahabiri
Kiswahili: Wadudu
Kreyòl ayisyen: Ensèk
кырык мары: Капшангы
лакку: Ущущулгъи
лезги: Пепеяр
Latina: Insecta
latviešu: Kukaiņi
Lëtzebuergesch: Insekten
lietuvių: Vabzdžiai
Limburgs: Insekte
lingála: Nyama ekɛ́
magyar: Rovarok
македонски: Инсекти
മലയാളം: പ്രാണി
मराठी: कीटक
მარგალური: ჭანდეფი (Insecta)
مازِرونی: بئو
Bahasa Melayu: Serangga
Mìng-dĕ̤ng-ngṳ̄: Tè̤ng-ngiê
монгол: Шавж
Nāhuatl: Yolcatzin
Nederlands: Insecten
Nedersaksies: Insekt
नेपाली: किरा
नेपाल भाषा: की
日本語: 昆虫
Napulitano: Inzetto
Nordfriisk: Insekten
norsk: Insekter
norsk nynorsk: Insekt
occitan: Insecta
олык марий: Шыҥа-копшаҥге
oʻzbekcha/ўзбекча: Hasharotlar
ਪੰਜਾਬੀ: ਕੀਟ
Pälzisch: Insekte
پنجابی: کیڑے
پښتو: خوځندکې
Patois: Insek
Plattdüütsch: Insekten
polski: Owady
português: Insetos
Qaraqalpaqsha: Shıbın-shirkeyler
română: Insectă
Runa Simi: Palama
русиньскый: Хробач
русский: Насекомые
саха тыла: Үөн-көйүүр
संस्कृतम्: जन्तुः
sardu: Babbalottu
Scots: Insect
Seeltersk: Insekte
shqip: Kandrra
sicilianu: Nzettu
සිංහල: කෘමියෝ
Simple English: Insect
slovenčina: Hmyz
slovenščina: Žuželke
Soomaaliga: Xasharaad
کوردی: مێروو
српски / srpski: Инсекти
srpskohrvatski / српскохрватски: Insekt
Basa Sunda: Gegeremet
svenska: Insekter
Tagalog: Kulisap
தமிழ்: பூச்சி
татарча/tatarça: Бөҗәкләр
తెలుగు: కీటకము
ไทย: แมลง
ትግርኛ: ሓሽራ
тоҷикӣ: Ҳашарот
lea faka-Tonga: ʻinisēkite
Tsetsêhestâhese: Meškêso
Türkçe: Böcek
українська: Комахи
اردو: حشرات
Vahcuengh: Non
vèneto: Bai
vepsän kel’: Gavedid
Tiếng Việt: Côn trùng
Võro: Mutuk
walon: Inseke
West-Vlams: Insektn
Winaray: Insektó
Wolof: Gunóor
吴语: 昆虫
ייִדיש: אינסעקט
Yorùbá: Kòkòrò
粵語: 昆蟲
žemaitėška: Vabzdē
中文: 昆虫