GROTON -- Residents in town have grown used to seeing bears, deer, moose, turtles and any number of other denizens of nature wandering local roadways or haunting backyard birdfeeders.

But it's safe to say that few if any have ever seen a herd of pigs running wild along less-frequented stretches of the rail trail.

Well, that's exactly what some have reported seeing over the past couple of weeks as a quartet of white and pink piglets were caught rooting around in the trailside brush.

Such an unusual sight was sure to come to the attention of animal-control Officer George Moore, who acknowledged that there was a group of pigs on the loose in Groton.

"They are probably 30-35 pounds apiece," Moore said. "They're still quite small. When I saw them on August 18, they were in the vicinity of John Crow Farm near Groton School. That's not surprising. They have quite a few pigs there, and I'm sure the loose pigs have been attracted by the noises and smells, etc. Also, when I saw them, the pigs were not confined but were outside of any enclosure at the farm."

Moore said he has no idea who the wild pigs belong to or where they might have come from.

"It's a mystery," said Moore, adding that he could not understand why the owners would not have come forward and identified themselves. "We've been watching different publications for notices and computer sites, but nobody has advertised for lost pigs."

Wild pigs (also known as wild hogs, wild boar or feral swine) are not native to the Americas but were introduced by European settlers as domesticated farm animals. The first wild pigs in the United States originated when domesticated pigs escaped from their owners and interbred with wild boars. The latter were also brought to the Americas for hunting purposes. The two species interbred, and today many hybrid populations exist in different parts of the country.

Described as an "opportunistic omnivore," a wild pig will eat almost anything, causing great damage to private property in his efforts to root out eatables. With no natural predators, the animals can grow vicious, with herds moving mostly from south to north.

"I don't know of any wild pigs in the Nashoba Valley," Moore said. "But I know New Hampshire has a problem with them and has a hunting season for wild boar. The situation there started years ago when well-to-do people started a game preserve then let it go. Fencing got poor and the pigs escaped."

Meanwhile, back in Groton, the loose piglets seem harmless enough.

"There's no chance that these pigs are wild," Moore said. "In fact, when I saw them the other day, if I stood quietly, they'd get curious and come over to me. Being attacked by one of them would be like being attacked by a cocker spaniel."

As to their being a threat to the public, Moore dismissed the notion ... for now.

"Right now, they're really cute little pigs, but once they start getting into somebody's roses or vegetable garden, it'll be a different story," Moore said. "Then they won't be so cute anymore. But if they're running in the road and get hit by a car, that could be a real hazard."

As of Labor Day weekend, the pigs seemed to be keeping a low profile.

"We've had several reports from the Police Department of sightings of the pigs, but nothing in the last week or so," Moore said on Aug. 26. "So I think they've settled in at John Crow Farm."

Should anyone take responsibility for the pigs, said Moore, they could not be sold for commercial consumption purposes.

"Any pig that is offered for sale on the market has to be fed on grain or something like that," Moore said. "They can't have eaten anything raw or natural. No one knows what these pigs have been eating. As such, they can't be offered for sale. So, if somebody caught them, they can use them for their own pork, but they can't sell it."

That said, the pigs cannot be allowed to remain loose.

"I talked with the Massachusetts Department of Agricultural Resources, and they said we should probably try to catch the pigs, and sooner rather than later," Moore said. "If they get to 150 pounds, they won't be cute anymore and can get aggressive. They also can get really destructive. We don't want that to happen.

"So what are we going to do? I have no idea yet. We'll have a consultation with local farmers and see what can be done. The pigs themselves are really skittish and won't be easy to catch. We'll have to come up with some type of plan. The pigs are OK right now, but they need to be headed off soon."

According to Moore, the little group of pigs has likely been reduced by one, with only three having been seen more recently. Still, he doesn't expect catching them will be as easy as one would expect.

"Pigs are really intelligent," Moore said. "If one learns something, the others will know it right away. You can only fool one pig one time."

So, if you should come across a curious group of cute little pigs while walking the town's byways, enjoy the sight while you can, because if carefully laid plans succeed, the animals may soon find their freedom at an end.