Why a Clif Bar Might Introduce You to the Indian Meal Moth

In early October, after a short trip, I came back to my apartment and saw a few small, copper and tan-colored moths flying slowly around in my kitchen and sitting on the cupboards. I also discovered the silky threads that insect larvae spin in packages of rice and walnuts that I had.

Looking around online, I learned I’d been infested by the Indian meal moth, a nuisance of food storage firms that, although harmless to people, likes to eat cornmeal (hence the name: Indian meal is ground corn), grains, nuts, and other dry foods.

There were no moth larvae crawling around, so there was no great cause for alarm: I wouldn’t need to fumigate the apartment, just throw out the infested packages and deal with the adults. For the next 10 days, I’d trap and throw out a few of the moths daily, which was easy: they don’t fly much, move slowly, have terrible peripheral vision, and usually move very little even once you’ve trapped them. After some days of hoping I’d see no more of the adults, one day none of them appeared, the next day was the same, and for about a week I thought the infestation was over.

I learned otherwise when I opened a bag of cereal one morning and a moth flew out. I made a more comprehensive run of the kitchen, swept over the cupboards, threw out some more food, put some packages in the refrigerator. The larvae of the Indian meal moth does not deal with cold well, and freezing food or just storing it at cooler temperatures is one way to end an infestation. I’d have to trap some more adults, though.

The next day I opened up a Clif energy bar, not at all suspectingly: the self-spun threads that these moths make were all over the surface of the bar. Opening a few more bars uncovered more threads and several adults stuck to the surface, dead. I’d eaten my last Clif bar. Going back online and searching for “indian meal moth clif bar,” I found this story from Gracie, a New York City blogger who spied the moth larvae on her half-eaten Luna bar (Clif makes Luna, Clif, Builder’s, and Mojo bars) a couple years ago. After sticking the bars in the freezer as evidence, I wrote to Clif, asking for some  compensation, and to Gracie.

The life cycle of the Indian meal moth ranges from six to eight weeks; the eggs hatch in two to 14 days. Apparently the moth larvae had arrived in the Clif bars I’d bought a few weeks before my trip. Most of them chewed through the bars’ wrappers to infest my apartment, pupating and getting into other food to lay eggs; the ones that didn’t make it died inside the packages. The larvae often pupate in cracks and crevices: there’s about a one-eighth inch gap between my cupboards and the ceiling, and my guess is they usually pupated in that gap, then emerged overnight and crawled down to the cupboards, where I would find them the next morning.

That’s the setup. A few days after writing to Clif, while still trapping a few adult moths a day, I got this explanation from them:

An adult moth will seek out a food source when it is ready to lay its eggs and can enter sealed packaging though microscopic pores or by biting through the wrapper.

While we do not know if the moth entered the packaging at the store level, in transit, or in storage, we are confident that the Indian Meal Moths you encountered did not originate in our warehouse or bakery. Our bakeries are kept scrupulously clean by using state-of-the-art pest control. Furthermore, an Indian Meal Moth simply could not survive the mixing and baking process. While this doesn’t make finding them in your bar any less unsettling, I wanted to assure you that they are not harmful, nor is it a common experience.

I hope that you will give our bars another chance. I would like to send fresh bars to you directly from our warehouse.

I am, sort of, giving their bars another chance: the Builder’s bars I asked for are said to be on their way to me now. They’re different enough from the Clif bars that I might be able to eat them, and if not I can always give the bars away. But, at about the same time I heard back from Clif, I also heard back from Gracie, the NYC blogger. She wrote: “It would be one thing if I experienced the only problem, but I’ve had dozens upon dozens of readers report the same issue as well.”

I’d also seen that there was a minor kerfuffle on the Internet about this, sparked by a guy on Reddit posting a picture of larvae on his Clif bar in, yes, early October, the same time my Indian meal moth experience began.

A few issues raised by all this: the Indian meal moths weren’t in the energy bars made by another company that I had in the cupboard adjacent to my Clif bars. So the explanation that the larvae dug their way into the Clif bars in transit, while supposedly true, doesn’t explain everything. If Clif doesn’t have a contaminated factory, and instead the bars were infiltrated at some point between production and retail sale, shouldn’t Clif address that problem by making a tougher wrapper? Or by investigating their supply chain and identifying the source?

In any event, I haven’t seen reports of the Indian meal moths associated with other energy/snack bars. It’s rash to say that Clif is certainly to blame here, but I’d never seen the moths before last month, so I’m not inclined to think Clif is an entirely innocent victim in these contaminations. I should add that I’d eaten dozens of Clif bars over the years with no problems, although lately I’d preferred sweeter, saltier,  better tasting snack/energy bars: Clif bars had come to feel like I was doggedly chewing through a mass of carbohydrates. And for all their talk about being organic and natural, Clif bars have less texture and less of a natural look to them than many other energy/snack bars. (The Mojo bar is their sweet/salty and natural-looking variety, but I haven’t tried it.)

Perhaps this is a temporary problem for Clif, one they’ve cleaned up in recent weeks. Perhaps they are indeed a victim, and I should give the bars another try rather than illogically conclude that all Clif bars are suspect. But why do that when there are other options available? And given the dramatic visuals and potential for outrage associated with this story, why hasn’t there been more publicity about the issue?

It’s silly to pretend that moths getting into Clif bars is a public health threat or a crisis, no matter what the exact cause is: the moths are harmless, it isn’t very hard to get rid of them. But at minimum, you do expect packaged food to be sufficiently sealed to prevent contamination, and it is clear that Clif’s packaging isn’t achieving that goal.