At Philly’s Barnes Foundation, the biggest art thieves can be smaller than your thumb.

AnnaLivia McCarthy slowly strolled a dimly lit gallery at the Barnes Foundation on a recent afternoon, casting her flashlight across the surfaces of masterpieces. As the museum’s senior conservation coordinator, McCarthy was not merely appreciating priceless art — she was hunting pesky prey. Sneaky intruders who hide in shadows and make meals out of masterpieces.

Moths, mostly.

“Sometimes you can see their eyes under the light,” McCarthy said, raking soft light on Secrets (Confidence) or Inspiration, an exquisite tapestry designed by Pablo Picasso and woven by Atelier Delarbre. “They have these little, beady black eyes.”

They, in this case, are the bane of art institutions the world over: the webbing clothes moth. These fluttering prowlers, identifiable by their small, golden bodies and tufts of golden-reddish hair, feast on natural fibers, like wool and silk. Undetected, the gilded insects chew away at textile surfaces and spin sticky tunnels through fabrics. Damage can be permanent.

“They like the cracks, crevices, and dark places,” said McCarthy, shining her light.

But the meddlesome moths only top McCarthy’s museum pest watchlist. Carpet beetles pose similar threats as their moth brethren. Wood-boring beetles burrow deep into furniture. Silverfish dine on paper, punching holes through books. (Thankfully, none of the bugs besiege the Barnes.) Then, there’s the 65 sticky traps hidden throughout the Barnes galleries and facilities, which can collar dust mites, millipedes, and the occasional wandering spider.

You can stop itching now. Because McCarthy’s weekly bug patrols at the Barnes, conducted on days the museum is closed to the public, are not cause for alarm. Nor are its treasured ensemble of Renoirs, Cezannes, and Matisses, African art, Native American ceramics, antiquities, and decorative iron work and furniture infested by armies of creepy-crawlers.

Keeping the bugs out is just part of the program.

Pest management has been an important part of preventative conservation practices in museums for more than three decades, said Barbara Buckley, senior director of conservation at the Barnes. As critical to the health of the collection as proper light, temperature, humidity, and cleanliness. It’s just not something museums usually wish to talk very much about, lest people get the wrong idea.

But last month, the museum cast aside any insect anxiety and posted a charming, engaging video on Instagram all about its pest prevention practices. Breezy pop played over footage of McCarthy making her rounds and checking traps. There was a photo of the dreaded webbing clothes moth — and even an image of Rizzo the Rat, the pizza-loving rodent from The Muppet Show. (Be calm: Mice are never found in the galleries, let alone rats, Buckley said, aghast. The social media folks just thought it was a funny photo.) All in all, fun fare.

The 60-second reel — part of a month-long campaign to highlight the museum’s sustainability efforts — notched nearly 17,000 views. It was the idea of Carolyn Rivera, brand engagement manager at the Barnes. Coming from a background in social media and TV, Rivera said she often looks to highlight interesting things she notices at the museum. Things that, well, longtime museum folks may take for granted, or not find very interesting at all. Like moths and sticky traps.

“It’s not the sexiest thing in the world,” she said, of pest prevention. “But it’s something that protects the artwork, the building, the people, the visitors. It’s integral to making everything work around here.”

The idea took a little arm twisting, admits Rivera, and one could understand the concern.

“That it could be taken the wrong way,” said Buckley, sheepishly. “That the museum is full of bugs.”

But Buckley‚ who keeps detailed records of any bug activity at the Barnes (so to better stomp out any threats), said that’s far from the reality. On average, only about five webbing clothes moths are found each month in the museum, she said. And typically in Annenberg Court, and the building’s lower levels, rather than the galleries. The Barnes maintained regular inspections during COVID-19 closures, a move, Buckley said, that may have helped prevent pandemic-related pest upticks other museums experienced. For example, the Getty Museum in Los Angeles, undertook a top-to-bottom moth remediation in 2021, after the pests penetrated deep into its galleries.

It was Buckley who first incorporated an extensive pest management strategy at the Barnes, shortly after she started working at the museum in 1992. Back then, the moths had dined on carpets from Dr. Barnes’ home that had been stored in the museum’s original gallery in Lower Merion. Buckley recalled how she and her graduate student interns spent “many summers” removing the insect’s gluey webbing with tweezers and handheld vacuums.

“It’s a slow, laborious process,” she said, wincing.

For her part, McCarthy said a passion for art and science fuels her work. Pests represent only a bit of her duties at the Barnes, which also include research and restoration. On her most recent inspection, which she cheerily dubs her “moth walks, she carefully checked a woolen Navajo blanket the color of sunrise, before scrutinizing a 19th-century table scarf. Finally, she scoured a series of beige silk and wool felt tapestries by Dutch artist Claudy Jongstra decorating the light-filled Annenberg Court. The towering textiles are a subtle nod to the Ramon Gold Israeli limestone that lines the great room’s walls — and a potential picnic for the golden-hued webbing clothes moth.

All were bug free.