Birds tend to attack standing cereals rather than stocks. They pose a significant threat between two crops.
Locust is the common name given to straight-winged jumping insects which, like crickets and grasshoppers, belong to the order Orthoptera. They can cause enough damage to plants.
The caterpillar is the larva of Lepidoptera, that is, insects whose imago is called a butterfly. The larvae of certain hymenoptera that closely resemble those of lepidoptera are called false caterpillars. They are voracious pests with a large appetite, damaging leaves and fruits.
Rodents can reach any source of human food, whether on the ground or in storage. Their small size and their mostly nocturnal way of life allow them to go unnoticed. Their presence is often only detected when damage appears, when the densities are already very high.