Family living site Disney Family Fun shows us how to repurpose an empty milk jug into a lunch container by washing it out, drawing lines as shown in the photo, cutting it out, folding, and attaching a hook and loop closure. This container is perfectly sized for a sandwich and a few carrot sticks or grapes. If you don't want to use this for food it also makes a clever gift box for small items.
"Sweet little metal box full of... mouses! Starting from this diagram of Mmmcrafts, you will be able to build from felt and fabric this house to hosting some small rodents that your children may carry wherever they want. Why not do 5 little monkeys? :)