ON THE downside, America's 6m or so feral pigs are dangerous pests armed with sharp tusks, short tempers and large appetites. A single herd, or "sounder," can wreck a corn crop or leave a meadow looking like a moonscape. They like to wallow in cool water and have fouled fishing rivers and swimming holes in dozens of states since an explosion in their numbers over the past 20 years. The hogs, descendants of colonial-era livestock and, more recently, European wild boars introduced for sport, spread diseases such as brucellosis, can breed twice a year and, when hungry enough, will eat lambs. On the upside, being clever and lean, they make for good hunting and - when cooked with skill - they are tasty. That dual nature, as pests with some value, makes crafting hog-control policies hard. In Michigan and Pennsylvania moves to ban the private rearing of feral pigs have seen fierce rows between wildlife officials and game-ranch owners, who dispute claims that soaring hog numbers are linked to escapes from shooting reserves. Missouri authorities allow pigs to be shot when they are stumbled on, but warn those sportsmen looking for dedicated hog-hunts to "do so in another state." Texas, home to America's largest feral-pig population, at around 2m, has a distinctive approach that takes account of a deep-seated hunting culture and the fact that around 95% of land is privately owned, making it hard for government to impose solutions. That is a challenge and an advantage, says John Davis of the Texas Parks and Wildlife Department. Nobody cares more deeply about land than a private owner, he notes. And there are two types of Texan landowner: those who have feral hogs already, and those who will. Texas urges landowners to control hogs with a range of measures, including trapping, culling from helicopters (legal since 2011 under what is known as the "pork chopper" law), and shooting with rifles, handguns and bows and arrows. Hunting hogs with dogs can be "very exciting," wildlife authorities advise, while the department's official YouTube channel carries a video on making "feral hog tacos." Technology is also being brought to bear. In Lockhart State Park, a country park south of Austin (and close to a new 85mph toll road that recently saw a spectacular hog-caused car crash), the superintendent, James Hess, shows off a large solar-powered corral trap. Anything moving in it is photographed, with images zipped to Mr Hess's mobile telephone, which can close the trap with a keystroke. To date he has been mostly woken at night by infrared snaps of raccoons, but the device will work, he thinks: simpler traps have already caught many pigs. The trick will be to catch whole sounders, because hogs are clever and learn from their mistakes. People too. The fight is on.