Crickets are small to medium-sized insects with mostly cylindrical, somewhat vertically flattened bodies. The head is spherical with long slender antennae arising from cone-shaped scapes (first segments) and just behind these are two large compound eyes. On the forehead are three ocelli (simple eyes). The pronotum (first thoracic segment) is trapezoidal in shape, robust, and well-sclerotinized. It is smooth and has neither dorsal or lateral keels (ridges).
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.
There are ten ways in which a batsman can be dismissed: five relatively common and five extremely rare. The common forms of dismissal are bowled, caught, leg before wicket (lbw), run out and stumped. Rare methods are hit wicket, hit the ball twice, obstructing the field, handled the ball and timed out. The Laws state that the fielding team, usually the bowler in practice, must appeal for a dismissal before the umpire can give his decision. If the batsman is out, the umpire raises a forefinger and says "Out!"; otherwise, he will shake his head and say "Not out". There is, effectively, an eleventh method of dismissal, retired out, which is not an on-field dismissal as such but rather a retrospective one for which no fielder is credited.
The ball is a hard leather-seamed spheroid, with a circumference of 22.9 centimetres (9.0 in). The ball has a "seam": six rows of stitches attaching the leather shell of the ball to the string and cork interior. The seam on a new ball is prominent and helps the bowler propel it in a less predictable manner. During matches, the quality of the ball deteriorates to a point where it is no longer usable; during the course of this deterioration, its behaviour in flight will change and can influence the outcome of the match. Players will, therefore, attempt to modify the ball's behaviour by modifying its physical properties. Polishing the ball and wetting it with sweat or saliva is legal, even when the polishing is deliberately done on one side only to increase the ball's swing through the air, but the acts of rubbing other substances into the ball, scratching the surface or picking at the seam are illegal ball tampering.
Cricket flour may be used as an additive to consumer foods such as pasta, bread, crackers, and cookies. The cricket flour is being used in protein bars, pet foods, livestock feed, nutraceuticals, and other industrial uses. The United Nations says the use of insect protein, such as cricket flour, could be critical in feeding the growing population of the planet while being less damaging to the environment.