What causes ulcers?

Why do ants drown themselves? Could we power cars with electrolytes? What causes ulcers? Do metal wrist rings actually reduce pain? Should you take probiotics on an ongoing basis? What are duodenal ulcers? Can brain tumours cause diabetes? Dr Chris Smith and Clarence Ford have all the answers... Like this podcast? Please help us by supporting the Naked Scientists (thenakedscientists.com/donate)