from this article
http://www.pittsburghlive.com/x/pittsburghtrib/news/cityregion/s_541372.html
Twelve airport employees are authorized to hunt in 24-hour cycles, primarily during hunting season, said airport spokeswoman JoAnn Jenny. The FAA requires airports to have wildlife management plans, but the USDA wants a more comprehensive approach to make areas at Pittsburgh International inhospitable to wildlife, such as eliminating standing water and reducing grass lengths.
Wow nothing like a private "high fence" for the good of mankind huh?