Crickets (also known as "true crickets"), of the family Gryllidae, are insects related to bush crickets, and, more distantly, to grasshoppers. The Gryllidae have mainly cylindrical bodies, round heads, and long antennae. Behind the head is a smooth, robust pronotum. The abdomen ends in a pair of long cerci; females have a long, cylindrical ovipositor. The hind legs have enlarged femora, providing power for jumping. The front wings are adapted as tough, leathery elytra, and some crickets chirp by rubbing parts of these together. The hind wings are membranous and folded when not in use for flight; many species, however, are flightless. The largest members of the family are the bull crickets, Brachytrupes, which are up to 5 cm (2 in) long.
Although the main object of the game has always been to score the most runs, the early form of cricket differed from the modern game in certain key technical aspects. The ball was bowled underarm by the bowler and all along the ground towards a batsman armed with a bat that, in shape, resembled a hockey stick; the batsman defended a low, two-stump wicket; and runs were called "notches" because the scorers recorded them by notching tally sticks.
Several types of cricket songs are in the repertoire of some species. The calling song attracts females and repels other males, and is fairly loud. The courting song is used when a female cricket is near and encourages her to mate with the caller. A triumphal song is produced for a brief period after a successful mating, and may reinforce the mating bond to encourage the female to lay some eggs rather than find another male. An aggressive song is triggered by contact chemoreceptors on the antennae that detect the presence of another male cricket.
During normal play, thirteen players and two umpires are on the field. Two of the players are batsmen and the rest are all eleven members of the fielding team. The other nine players in the batting team are off the field in the pavilion. The image with overlay below shows what is happening when a ball is being bowled and which of the personnel are on or close to the pitch.
Captive crickets are omnivorous; when deprived of their natural diet, they accept a wide range of organic foodstuffs. Some species are completely herbivorous, feeding on flowers, fruit, and leaves, with ground-based species consuming seedlings, grasses, pieces of leaf, and the shoots of young plants. Others are more predatory and include in their diet invertebrate eggs, larvae, pupae, moulting insects, scale insects, and aphids. Many are scavengers and consume various organic remains, decaying plants, seedlings, and fungi. In captivity, many species have been successfully reared on a diet of ground, commercial dry dog food, supplemented with lettuce and aphids.