I recently bought a 40 lbs bag of Dominican dog food (well, it didnt look imported) that was infested with these small black bugs, approxiamately 4 to 7 mm in size. Originally I thought they were small baby cockroaches, but they are not getting bigger, and now they are multiplying in my house and getting everywhere, especially in bread, flour, and other foods. They know how to fly and swim (while I seldom see them do this), and are hard to crush. They are definitly not cockroaches, are slim in shape, and very black in color. Does anybody know what they are, and how to get rid of them?