For the past six years the Ministry of Agriculture has been tackling the problem of TB in badgers in a few areas in south-west England by gassing all infected sets and those in immediately adjoining territories as dangerous contact, with the expectation of eliminating all the infected badgers. The author points out that because TB is a stress disease, and because it is impossible to gas every badger in a group simultaneously, gassing may be driving infected individual badgers to join other groups and infect them, thus actually spreading the disease.