Photo: nedjelly/iStock

6 of 8
The Ingredient You Bought Way Too Much Of
Many of us buy flour in bulk and store it until we need it for holiday baking—giving pantry pests plenty of time to creep their way in. Because flour has a shelf life of three to six months (up to eight months if stored properly), we typically don't think twice about letting it linger in our cupboards; but unless you have it stored in a glass or airtight container, reddish-brown flour beetles can easily make their way inside and lay their hard-to-see eggs, says Andrew Callaghan, a Terminix pest-control company branch manager in Chicago. These pests can be up to six millimeters in length, so they are pretty easy to spot; but if that crumpled flour bag leaves you in doubt—toss it out. And even if your flour is in an airtight container, you should inspect it carefully before using.