A rat infestation is spelling trouble for the almond industry

The world is seemingly going to the rats, as the United Kingdom is currently facing a significant infestation of rodents. But the U.K. isn't the only place dealing with rat issues, as several thousand miles away, California farmers are trying to fight off an infestation that is causing significant problems for the almond industry.

This influx of rats could devastate not only the almond supply in the U.S. but globally. All of America's commercially grown almonds are produced in California, and the Golden State is responsible for 80% of the world's almond supply, according to the USDA, so producers are trying to stop the rats before they get out of control.

What is happening with the rats?

Almond growers are "facing an unprecedented challenge this season as a severe roof rat infestation" affects portions of California's Central Valley, said the Almond Board of California. Farmers have "reported an alarming spike in rodent populations." The rats are likely "using irrigation canals and other waterways as corridors, enabling them to rapidly spread between orchards and diverse agricultural fields."

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These roof rats, commonly called black rats or house rats, are "arboreal, meaning they spend a considerable amount of their life above ground, often building nests in trees," said the Almond Board. But over the last several years, researchers have "noted that in almonds and other tree nuts, they use burrows extensively."

There is "no clear-cut explanation for why rats on a large scale" suddenly "developed a taste for nut trees," said USA Today. But if a solution is not found, it could decimate the almond industry, as the infestation has already "impacted more than 100,000 acres and caused $109 million to $311 million in losses from damage to equipment and crops over a year." And the rats just keep coming; at least one almond grower said he was "exterminating between 50-100 rats a day," according to the Almond Board.

How are almond farmers fighting back?

Growers have been "caught off-guard by the recent explosion of rodents across the state," said Roger Isom, chief executive of the Western Tree Nut Association, to the Los Angeles Times. California farmers have "never really had a rat issue in almonds ... so we weren't looking for it, or treating for it, or preventing it."

For now, farmers are implementing a number of methods to halt the flow of rats. They are "using bait stations and aluminum phosphide treatments in burrows in the winter and, during non-winter months, are turning to snap traps, owl boxes and fumigating the rats by applying carbon monoxide" into rat burrows, said the Times. But these methods are often labor-intensive and expensive.

Before deploying these traps, farmers "should track the rodents and use game cameras to pinpoint hotspots," said Patch. They should also make "fresh bait available for at least four weeks, followed by longer-term use" for traps.

But there are still concerns among farmers that these procedures simply won't be enough to ward off the infestation. "We've never seen anything like this," Isom told USA Today. "I've had growers who have lost more than half their yield. We're not going to know until this year's crop is in whether it was just weather-related or it was due to rat damage. It has certainly affected orchards. Hopefully we can get ahead of this thing and prevent it from becoming a big, big issue."