while 50% of the six national airports and 14.3% of the 14 regional airports did leave their grass long, primarily intending to discourage gull and goose usage. The two most common grass mowing practices, each reported by 32.1% of respondents, were: all practical areas were mowed regularly, but the height to which they were mowed was not specified; and the grass was kept short, either to reduce nesting or reduce rodent populations. One small and 2 regional airports only cut their grass once per year.