California’s $4.7 billion almond industry is under siege from rats, which have infested more than 100,000 acres in the San Joaquin Valley.
Losses over the past year are estimated between $109 million and $311 million, according to the Almond Board of California.
The rat infestation is tied to a mix of abandoned farmland left unplanted during drought years, a rebound in vegetation following recent rains, and pesticide restrictions that limit control options.
Rats are devouring almonds and also chewing through irrigation lines, electrical wiring, and tree bark, sometimes even causing fires.
Farmers are spending hundreds to thousands of dollars per acre on control measures ranging from fumigation to bait stations and owl boxes.
Experts warn the outcome of this year’s harvest—expected to be one of the largest on record—will reveal whether the outbreak is a temporary spike or a long-term threat to the industry.