FBI agents wearing white moon suits and gas masks scoured the newspaper offices of two men whose exposure to anthrax has prompted heightened fear of bioterrorism across the country. The search turned up no further sign of anthrax in Robert Stevens' Florida office since traces were discovered on his computer keyboard. Stevens, a photo editor with the Sun tabloid newspaper, died last week of inhaled anthrax, a rare, particularly lethal form of the disease. Anthrax cases are rare in humans. The disease is much more commonly found in animals. Today, the University of Minnesota's Center for Animal Health and Food Safety is sponsering a teach-in on bio and agro-terrorism. Dr. Will Hueston (Houston) is the director of the Center. He says his veterinary students could play a key role in the fight against terrorism.