in 42 of 50 American states and is the most common trapping method. Animals used in science In the US, every institution that uses vertebrate animals for federally funded laboratory research must have an Institutional Animal Care and Use Committee (IACUC). Each local IACUC reviews research protocols and conducts evaluations of the institution's animal care and use which includes the results of inspections of facilities that are required by law. The IACUC committee must assess the steps taken to "enhance animal well-being" before research can take place. This includes research on farm animals. According to the National Institutes of Health Office of Laboratory Animal Welfare, researchers must try to minimize distress in animals whenever possible: "Animals used in research and testing may experience pain from induced diseases, procedures, and toxicity. The Public Health Service (PHS) Policy and Animal Welfare Regulations (AWRs) state that procedures that cause more than momentary or slight pain or distress should be performed with appropriate sedation, analgesia, or anesthesia. However, research and testing studies sometimes involve pain that cannot be relieved with such agents because they would interfere with the scientific objectives of the study. Accordingly, federal regulations require that IACUCs determine that discomfort to animals will be limited to that which is unavoidable for the conduct of scientifically valuable research, and that unrelieved pain and distress will only continue for the duration necessary to accomplish the scientific objectives. The PHS Policy and AWRs further state that animals that would otherwise suffer severe or chronic pain and distress that cannot be relieved should be painlessly killed at the end of the procedure, or if appropriate, during the procedure." The National Research Council's Guide for the Care and Use of Laboratory Animals also serves as a guide to improve welfare for animals used in research in the US. The Federation of Animal Science Societies' Guide for the Care and Use of Agricultural Animals in Research and Teaching is a resource addressing welfare concerns in farm animal research. Laboratory animals in the US are also protected under the Animal Welfare Act. The United States Department of Agriculture Animal and Plant Health Inspection Service (APHIS) enforces the Animal Welfare Act. APHIS inspects animal research facilities regularly and reports are published online. According to the U.S. Department of Agriculture (USDA), the total number of animals used in the U.S. in 2005 was almost 1.2 million, but this does not include