As Rats Lay Siege to Crops, a Pied Piper Steps In

This remote farming town in northwestern Mexico has tried just about everything to rid itself of rats: cats, poison and even cash rewards for killing the thousands of rodents infesting businesses and destroying the corn harvest.

So when retired Massachusetts salesman Stephen Petren called and said he had a foolproof method, local officials took him up on it.

Now, Petren, who speaks no Spanish, is using hand signals to teach Mexicans how to exterminate vermin.

Petren, 71, from Holliston, Mass., decided that he could help this town of 3,000 in the rugged Tarahumara mountains after reading an article about farmers battling a plague of rats. He flew to El Paso, Texas, where he met Mexican officials who drove him 16 hours to Atascaderos, which translates roughly as “Mud Holes,” and put him up at the only hotel for miles.

“My family thinks I’m crazy for coming here because they couldn’t even find Atascaderos on a map,” said Petren, who once sold chemicals used in makeup, shaving cream and shampoo. “But I made up my mind, and decided I wanted to come and help.”

Villagers started noticing the rodent problem a year ago when rats appeared in barns and corn storage sheds.

Most believe that the rats traveled from Chihuahua City, about 300 miles to the north, hidden among wooden poles that were brought in to set up the village’s electricity two years ago.

Earlier this year, the rats, which are able to produce 800 offspring per year, started eating corn from the fields.

Desperate farmers started setting out traps and poison, but the effort backfired: Cats and other animals that prey on rats were killed instead. With the predators dead, the rat population exploded.

Petren came armed with molasses, empty oil drums, paper and string for a method he learned in 1951 from his biology professor, a World War II soldier who served in France.

Last weekend, farmers wearing sweat-stained straw hats and sandals gathered at the town’s dance hall around the affable, gray-haired American, who looked out of place in his khaki pants and hiking boots.

“We’re not bringing a magic flute, but Mr. Petren has an idea to help control the problem, and we have to give him a chance,” said Luis Martinez, the state pest control official who brought Petren to Atascaderos.

With some translation help from this reporter, Petren showed the men how the open end of the drum had to be covered tightly with paper and secured with string. A mix of molasses and corn would be placed on top of the drum as bait, and a ladder would have to be built with wood or empty boxes so that the rats could have easy access.

“The rats will have to be fed for six days and on the seventh day, the magic happens,” Petren told the farmers.

The magic, Petren said, consists of cutting a cross through the paper, filling a third of the drum with water and removing the last step on the ladder.

“The rats will come to get their dessert, and they will be forced to jump and will fall in the drum and drown,” Petren said as the men looked at him with blank expressions.

Until coming to Mexico, Petren had never tried the technique to kill rats. But he set up a few drums as examples and the men bombarded him with questions. Could they use apples as bait? Could they set up drums in the fields? Could they cut the drum open on the fourth day as opposed to the seventh?

Petren’s answer: You have to try and see.

Results were spotty on the first few nights, with no real signs that the rats had dined at the barrels. But Carlos Valenzuela, a member of a committee formed to fight the rats, said he believed that soon, rats would start falling in the traps.

“We have been using buckets of water filled with oats, and we have been drowning rats that way. So I’m sure this would help kill even more of them,” he said.

John Fasoldt, owner of United Exterminating Co. in Cherry Hill, N.J., said the success of using drums with bait will depend on whether the rodents are hungry. But with plenty of corn and other produce in Atascaderos, Fasoldt doubts that Petren’s method will succeed.

“Something like that will work with mice, but it may not be as successful with rats because they are much more intelligent than other rodents,” Fasoldt said. “He may catch a few, but I don’t think it’ll solve their problem.”