This information was taken from the Fairfax County Public Schools site which is no longer published.
Field crickets are the crickets everyone sees and hears in late summer and fall. They grow up to an inch long, and are black and brown or sometimes red. They have large hind legs and two cerci (spiky things coming out of the back of their abdomens).
Female field crickets also have an ovipositor. An ovipositor is the longer spiky thing (about 3/4 inch) coming from the abdomen between the cerci.
Field crickets live mostly in fields and forest edges.
Why do they chirp?
Once field crickets are fully grown (about a month and a half after they are born) they will look for a mate. Male crickets chirp or "sing" to attract females and as a warning to other males to stay away from their territory. Female crickets can't chirp. The "song" is made by rubbing the front wings together. Since baby crickets are born in the spring, summer means they finally have fully developed wings and are able to rub them together to produce a sound. By the end of summer and beginning of fall as more and more crickets mature, they can be heard—often quite loudly—in the evenings. Females hear the song through tympanum (eardrums) on their front legs. Once a female approaches a male, he will do a move back and forth in a sort of courtship "dance."
For most species of cricket, the warmer the weather, the faster they chirp. One species of cricket, the snowy tree cricket, has been found to have such a regular chirp rate that counting the number of its chirps in 14 seconds and adding 40 will accurately tell you what temperature it is! Field crickets are most active at night. The songs of many males can be heard on summer and fall evenings. The song is usually a high trill played in threes.
After mating, female field crickets look for some damp soil to lay eggs. They inject their ovipositors, like a needle, deep into the soil. She will lay about 50 eggs at a time through her ovipositor. One female can lay over 400 eggs in her short life.
Field cricket eggs hatch in the spring, usually May. Young crickets are called nymphs. Nymphs eat a lot and grow quickly. They will molt (shed their outer skin) eight or more times as they grow up. With each molt, the nymphs look more and more like an adult. Young nymphs basically look like a cricket with no wings.
Field crickets do not survive over the winter. Any adult crickets or nymphs will die when cold weather arrives. Eggs, however, overwinter. They will survive and hatch the following spring.
Field crickets eat plant material, especially seeds, small fruits, and living and dead insects. If they are really hungry, they will even eat each other!
Predators of the field cricket include birds, frogs, toads, turtles, and other insects.
I often struggle to find websites with quick, simple lessons to help kids understand some basic concepts, so I decided to create some of my own for those I can't find elsewhere!