Your pantry may be harbouring thousands of pests known as stored product insects.
Signs of an infestation:
Insects that infest barley, rye, corn, oats, rice and various other seeds (the eggs of which are laid and hatched inside kernels of wheat or corn, or other whole grains or caked materials):
Insects which feed on processed grains or broken kernels, or a variety of spices:
Generally speaking the greater the number of insects, the older the infestation. Often the initial source is partially used boxes or bags of products that have been forgotten in the backs of pantries and shelves. Disposal of infested materials is the best way to eliminate the problem. Also check all items in pantries or on shelves. Often beetles can be found beneath cans and other items.
What you can do:
Treatment: