Let the treats cool completely before storing them. Place them in an airtight container, layered with the treats with wax paper or a piece of parchment paper to prevent them from sticking together. Store the container in a cool, dry place away from direct sunlight. Rice Krispie treats will stay fresh for up to 3-4 days when stored properly. If you need to store the treats for longer than 3-4 days, you can freeze them. Wrap each individual treat in plastic wrap and place them in a freezer-safe container. The treats will keep in the freezer for up to one month.