Yes, Ed. They can. So can cans of chili, cans of Campbell's soup, and bottle of Coca-Cola. Taking the bullet out of .22 shell and some tobacco out of a cigarette, pouring the powder from the .22 into the cigarette and then carefully replacing the tobacco was another thing well-thought of in Certain Sections of the country among Certain People I could name but shan't. So was urinating on someone else's campfire. Ah, for the days of my youth!