The other day I decided to make some bread for the first time in a few weeks. Imagine my horror when I spotted tiny creatures creeping around on the surface of my strong white flour. On inspecting further I discovered them in ALL of my packets of flour, baking powder and even rice, there were even a few in a packet of sugar that I bought last week and HADN'T EVEN OPENED. Frantic research on t'internet revealed that they were flour mites, and that they smell minty (DGS wailed 'Granny, my toothpaste smells minty!') and can give you something called 'Grocers' itch'. They can nibble their way through cardboard packaging, and their eggs are often present in shop bought dry goods, but can be prevented by putting all such items in the freezer in a plastic bag for four days after you bring them home.
Who knew!!