The Animal Damage Control Act of 1931 provided broad authority for investigation, demonstrations and control of mammalian predators, rodents and birds. P.L. 99-19, approved in 1985, transferred administration of the act from the Secretary of the Interior to the Secretary of Agriculture. P.L. 102-190 in 1991 added provisions directing the Secretaries of Defense and Agriculture, respectively, to take actions to prevent the introduction of brown treesnakes into other areas of the U.S. from Guam. P.L. 106-387, effective in October 2000, amended the act to give broad authority to the Secretary of Agriculture in carrying a wildlife services program with respect to injurious species.