The Brand names include Havoc, Talon, Contrac, Maki, Ratimus and d-CON Mouse Pruf II. The EPA now is moving to curb widespread use of these rodenticides, starting next June. That move, however, could be short-circuited by a lawsuit filed by the multinational corporation the sells d-CON products. Pesticide manufacturers, applicators and health officials say controlling rats is an important public health goal because they can spread a number of diseases, including hemorrhagic fever, leptospirosis, salmonellosis and rat bite fever.