If you’ve paid any attention to the precarious state of ecological systems around the world, you’re probably aware that bees are dying at an alarming rate. Though it’d be easy (and accurate) enough to assign the blame to the broad category of climate change, beekeepers in the U.S. have honed in on one specific culprit which seems to be responsible for an outsized percentage of bee fatalities: America’s growing obsession with almond milk.

A recent report by The Guardian explains how California’s $11 billion almond industry depends on nearly two thirds of all commercial honeybees in the U.S. to fertilize the plants that make up the state’s massive Central Valley almond groves.

Though it’s lucrative business, the almond pollination process, which one senior scientist at the Center for Biological Diversity described as “like sending the bees to war,” exposes bee colonies to a variety of threats. Almonds are often doused with more pesticides like herbicide glyphosate (the active chemical compound in Roundup) than other crops, and the industrial scale of their production means that growing areas forsake all other crops that bees enjoy.

Other factors also upset the bee population and expose them to greater risk. The schedule of almond pollination can also be jarring, as it starts a good one to two months earlier than bee colonies would normally emerge from winter dormancy. The intense concentration of the country’s bees in one place also makes them far too susceptible to the spread of sickness or mite infestation.

The end result is routine losses of around 30 percent of a beekeeper’s supply and a total of 50 million bees for the 2018-19 season, a situation that Almond Board of California pollination consultant Bob Curtis described as “too high and unacceptable” for both sides.

That leaves beekeepers, who can often make upwards of $200 per hive sent to pollinate almonds, in a tough situation. It’s not unheard of for major beekeepers to spend around $50,000 to replace the bees they lost in the annual pollination process, and expenditures on mite treatments and other preventive measures are often just as significant.

To cut back on the millions of bee deaths, beekeepers and almond producers will need to arrive at a more sustainable production process that breaks from current factory-style, monocultural crop production. The Xerces Society, a nonprofit behind the “Bee Better” certification program adopted by companies like Haagen-Dazs, touts the benefits of biodiversity to help honeybees work better while avoiding pests. Simultaneously, tamping down on pesticide use would save many bees, with The Guardian noting that one almond grower has sacrificed about 10,000 pounds of annual yield to keep his 20-acre farm pesticide-free.