Adults of the merchant grain beetle, Oryzaephilus mercator Fauvel, were found most frequently in bran, shelled sunflower seeds, rolled oats, and brown rice in a series of tests of up to 18 different household foods and oilseeds. Walnuts and flaxseed ranked next among the preferred foods. Wide fluctuations in preference occurred with bran, bread crumbs, and soda crackers. In a test of sunflower seeds, rolled oats, and bran all were equally preferred. Few beetles were found in wheat germ flakes, cornflakes, whole rapeseed, and raisins, and one or none in flour, a mixture of flour and brewers’ yeast (95:5, w/w), pancake mix, shredded coconut, and crushed or pulverized rapeseed. The same foods, in pulverized form, contained few or no beetles, indicating that food density affects insect distribution.