There are 27 native species of grasshoppers and crickets (Latin name Orthoptera) in the UK and they are relatives of cockroaches, earwigs, stick-insects and mantids. Like dragonflies, they have an incomplete metamorphosis so they don’t have a pupal stage and the immature stages (called nymphs) look like the adults. There are a couple of ways of telling the two groups apart. Grasshoppers generally have short, thick antennae while crickets have thin antennae which are usually longer than their bodies. Female crickets normally have long, sword shaped egg-laying tubes (ovipositors) while the grasshopper’s ovipositors are not as obvious.
Male crickets and grasshoppers are very noisy and it is thought they chirp to attract a mate and defend their territories from other males. Generally male grasshoppers make the sound by rubbing pegs on the inside of their hindlegs against a raised vein on their front wings, while crickets rub their wings together. You can get a good idea of the temperature by timing the number of chirps in 15 seconds. The fewer there are the cooler the temperature.