Tetramethylenedisulfotetramine (2,6-dithia-1,3,5,7-tetraazadamantane, 2,2,6,6-tetraoxide, TETS) is a highly toxic heteroadamantane rodenticide. It is an odorless, tasteless, white crystalline powder that is slightly soluble in water (0.25 mg ml^-1), dimethyl sulfoxide and acetone. It was originally synthesized in 1933 as a resinous condensation product of sulfamide and formaldehyde and used commercially in pillows and upholstery as an impregnating stiffening and antimold agent. However, in 1950, a massive poisoning of German workers in the furniture manufacturing industry was linked to ‘Crinex’ wool, which contained TETS as a byproduct of processing. Early experimental studies in rodents revealed that TETS was an extremely toxic convulsant agent. It was also discovered at this time that TETS is a highly effective rodent repellent, which resulted in its use during reforestation projects to prevent seed predation by rodents. However, because of its high toxicity in mammals, including humans, and its persistence in the environment, many countries banned its production and use in 1984. This ban became worldwide when China issued similar restrictions in 1991. However, due to its relative ease of synthesis and low cost, TETS remains available on the black market, particularly in many rural areas of China and in regions outside of China that have large Asian populations.