Shooting pigs from a helicopter is legal in Texas, and can be an effective method, killing as many as 9 to 27 animals per hour. However, helicopters can cost from US$400 to US$1000 per hour to operate. These costs are defrayed by selling seats on these helicopter flights to recreational hunters; Texas law only requires that those buying a helicopter hunt be in possession of a hunting license. The method relies on the helicopter flushing pigs into the open where they can be targeted. In some areas, such as the Piney Woods, this may not be possible because of vegetation.