Besides from the obvious loss that is caused by pests eating stored food, there is also the large amount of food that is thrown away as a result of the mere presence of pests. Goods containing pests can change significantly in proportion to the declared content and quality. The weight of products can change due to respiration from pests and damage to the packaging which results in loss of some of the goods. The declared content of nutrients shifts to the worse, because pests eat selectively. Pests tend to eat the healthiest parts of the goods and then leave excrements behind. Texture and consistency can change, moth web, visible lumps of excrements, dead, rotting pests, discolouration and unpleasant smells can occur. These are all results of infestations, which all makes goods useless as food for people.
A part of the goods which are thrown out are probably still acceptable for consumption. However, it is thrown away because food pests are not tolerated in goods. In western countries, pests cost us up to 5 % of the value of all produced food.