What are Psocids?
Psocids are common but harmless household pests, smaller than a pinhead (usually about 1 - 1.5 mm long) that are attracted to dry powdery type foods. They do not like the light but prefer to live in dark, warm, humid places such as the folds of packaging in food cupboards. They can live for about six months and in that time a female will lay up to 200 eggs.
They are not caused by poor hygiene; they are just as common in scrupulously clean homes as they are in the not-so-clean.
What Causes Them?
What is certain is that they are always associated with damp. It could be caused by new plaster drying out, it could be condensation from not having enough ventilation in the kitchen, it could be a leaky water pipe. There are many reasons but you can be sure that if you have psocids you have humid conditions. They feed on mould caused by damp conditions.
How are they Prevented?
Always keep your dry foodstuffs, cereals and the like, in a cool dry well ventilated place. Clean out your cupboards regularly but if you use water, always make sure that they are completely dry before you put the food back.
When you are cooking or boiling the kettle or even just using the washing machine or tumble drier, make sure that the kitchen is properly ventilated.
How to Get Rid of Them if They Appear
Remove the affected food immediately and dispose of it outside. Check everything else in the cupboard. Food cans and bottles will still be all right but make sure that there are no insects hiding under the labels. Treat the infected area with a good household insecticide which is suitable for use near food. Clean out all the dust, crumbs etc, then make sure the cupboard is completely dry.
Having done that, find the cause of the humidity and cure it.