Some species, such as the ground crickets (Nemobiinae), are wingless; others have small fore wings and no hind wings (Copholandrevus), others lack hind wings and have shortened fore wings in females only, while others are macropterous, with the hind wings longer than the fore wings. In Teleogryllus, the proportion of macropterous individuals varies from very low to 100%. Probably, most species with hind wings longer than fore wings engage in flight.
The batsman on strike (i.e. the "striker") must prevent the ball hitting the wicket, and try to score runs by hitting the ball with his bat so that he and his partner have time to run from one end of the pitch to the other before the fielding side can return the ball. To register a run, both runners must touch the ground behind the popping crease with either their bats or their bodies (the batsmen carry their bats as they run). Each completed run increments the score of both the team and the striker.
Most bowlers are considered specialists in that they are selected for the team because of their skill as a bowler, although some are all-rounders and even specialist batsmen bowl occasionally. The specialists bowl several times during an innings but may not bowl two overs consecutively. If the captain wants a bowler to "change ends", another bowler must temporarily fill in so that the change is not immediate.
Off the field in televised matches, there is usually a third umpire who can make decisions on certain incidents with the aid of video evidence. The third umpire is mandatory under the playing conditions for Test and Limited Overs International matches played between two ICC full member countries. These matches also have a match referee whose job is to ensure that play is within the Laws and the spirit of the game.
Crickets have a cosmopolitan distribution, being found in all parts of the world with the exception of cold regions at latitudes higher than about 55° North and South. They have colonised many large and small islands, sometimes flying over the sea to reach these locations, or perhaps conveyed on floating timber or by human activity. The greatest diversity occurs in tropical locations, such as in Malaysia, where 88 species were heard chirping from a single location near Kuala Lumpur. A greater number than this could have been present because some species are mute.
A match's statistics are summarised on a scorecard. Prior to the popularisation of scorecards, most scoring was done by men sitting on vantage points cuttings notches on tally sticks and runs were originally called notches. According to Rowland Bowen, the earliest known scorecard templates were introduced in 1776 by T. Pratt of Sevenoaks and soon came into general use. It is believed that scorecards were printed and sold at Lord's for the first time in 1846.
In 1975, Dr. William H. Cade discovered that the parasitic tachinid fly Ormia ochracea is attracted to the song of the cricket, and uses it to locate the male to deposit her larvae on him. It was the first known example of a natural enemy that locates its host or prey using the mating signal. Since then, many species of crickets have been found to be carrying the same parasitic fly, or related species. In response to this selective pressure, a mutation leaving males unable to chirp was observed amongst a population of Teleogryllus oceanicus on the Hawaiian island of Kauai, enabling these crickets to elude their parasitoid predators. A different mutation with the same effect was also discovered on the neighboring island of Oahu (ca. 100 miles (160 km) away). Recently, new "purring" males of the same species in Hawaii are able to produce a novel auditory sexual signal that can be used to attract females while greatly reducing the likelihood of parasitoid attack from the fly.
Most crickets lay their eggs in the soil or inside the stems of plants, and to do this, female crickets have a long, needle-like or sabre-like egg-laying organ called an ovipositor. Some ground-dwelling species have dispensed with this, either depositing their eggs in an underground chamber or pushing them into the wall of a burrow. The short-tailed cricket (Anurogryllus) excavates a burrow with chambers and a defecating area, lays its eggs in a pile on a chamber floor, and after the eggs have hatched, feeds the juveniles for about a month.
The ICC also organises competitions that are for several countries at once, including the Cricket World Cup, ICC T20 World Cup and ICC Champions Trophy. A league competition for Test matches played as part of normal tours, the ICC World Test Championship, had been proposed several times, and its first instance began in 2019. A league competition for ODIs, the 2020–22 ICC Cricket World Cup Super League, is planned to begin in 2020. The ICC maintains Test rankings, ODI rankings and T20 rankings systems for the countries which play these forms of cricket.