Many species of insects (probably 1000 or more) have served as traditional foods among indigenous peoples, especially in warmer climes, and the insects have played an important role in the history of human nutrition. As part of the hunter-gatherer style of life, the main criteria for selection of these traditional species appears to be medium-to-large size and easy availability, i.e., abundance, as noted by Dufour and others. Thus it is not surprising that many insects considered as crop pests in modern agriculture have served as important food sources. Locusts and grasshoppers, which often occur in swarms, are good examples, and these insects have been included in the diets of almost every culture with any history of food-insect use.