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.
Crickets have from time to time appeared in poetry. William Wordsworth's 1805 poem The Cottager to Her Infant includes the couplet "The kitten sleeps upon the hearth, The crickets long have ceased their mirth". John Keats's 1819 poem Ode to Autumn includes the lines "Hedge-crickets sing; and now with treble soft / The redbreast whistles from a garden-croft". The Chinese Tang dynasty poet Du Fu (712–770) wrote a poem that in the translation by J. P. Seaton begins "House cricket ... Trifling thing. And yet how his mournful song moves us. Out in the grass his cry was a tremble, But now, he trills beneath our bed, to share his sorrow."