Crickets swarms are not uncommon,because when they travel in large groups they have a better survival rate. About 50 percent of them die when they split up compared to when they don't. However, swarms can be a nuisance,especially for farmers,because they damage their crops. Many crickets are nocturnal and they make a chirping noise by rubbish their wings together. However,the colder it gets,the slower crickets chirp.