Navigating past the enormous hanging blue whales and the Alaska brown bear on the ground floor of the American Museum of Natural History, you’ll stumble upon an unassuming, concealed door. Above it are small signs.

“Bug colony.”

Behind this door, accessible solely to a select group of museum staff, thousands of carnivorous skin beetles tirelessly work around the clock, carrying out specimen preparation tasks that even the museum’s most skilled professionals cannot manage.

They consume the flesh from animal skeletons, leaving only pristine bones behind.

Many skeletons are too intricate for human cleaning, so the museum’s osteologic preparation team turns to these six-legged workers to ready specimens for research and display.

The operation takes place in three gray wooden boxes, about the size of a foot locker, which house the colony. These boxes are lined with stainless steel, and their flexible tops unveil a range of small creatures, including beetles, feasting on the remnants of primarily birds. They devour morsels of flesh still attached to the carcasses.

The room resonates with soft, crackling noises. “Adding milk makes it sound like frying food or cooking rice,” mentioned Rob Pascocello, a colony caretaker.

The beetles are tiny—only a few millimeters long—capable of entering the narrowest crevices in animals and nibble away without damaging fragile skeletal structures, according to Scott Schaefer, the overseer of the museum’s vast collection of specimens and artifacts, which comprises over 30 million items.

“They do an exceptional, meticulous job that human hands cannot replicate due to delicacy,” Schaefer explained. “It’s gentler than boiling the specimens or subjecting them to chemicals or acids.”

Museum representatives state that this industrious colony has processed countless carcasses, including a significant portion of the over 30,000 bird skeleton specimens housed for decades. “They slip into tiny spaces and go unnoticed, continuing to feed until there’s nothing left,” Schaefer noted.

On a recent weekday, Paul Sweet, the collection manager for ornithology, stood in the bug room, pointing out that the name is misleading from a scientific standpoint.

True bugs, known scientifically as Hemiptera, have mouthparts designed for piercing and sucking. In contrast, beetles—known as Coleoptera—typically have a cylindrical shape with chewing mouthparts.

The colony has effectively reduced the once vibrant pink flamingos into mere bundles of bones. The majestic snowy owl was similarly transformed. Among the remnants was a tiny skeleton in a canister, with bones smaller than a toothpick.

“That’s a songbird,” Pascocello remarked.

Skin beetles are scavengers commonly found in the wild, nests, and animal burrows, feasting on deceased animals.

Museum officials mentioned that this dermatological colony, introduced from Africa in the 1930s, has remained self-sufficient. Sweet noted that the current beetle population has been at the museum for 35 years, though it remains uncertain whether they are descendants of the original colony.

Regardless, beetles only live for six months, leading Pascocello to humorously state, “they’re all related.” He also mentioned having a backup colony in his bedroom during the museum’s closure due to the coronavirus pandemic.

On this particular day, Sweet was preparing to feed the colony a Northern Gannet, a seabird recovered from Midland Beach on Staten Island. It had already been stripped, dried, and had most of its meat removed by researchers before being handed over to the beetles for final preparation.

Within minutes, the bodies were swarming with beetles. While smaller birds can be entirely cleaned in just a couple of days, a larger skeleton, like that of a gannet, may take up to two weeks.

Pascocello once provided beetles to feed orangutans, while Sweet had given them the remains of an emu. However, the size of the specimens presented determines how they are handled; larger ones must be provided in pieces, such as the remains of a Cuban crocodile named Fidel, sourced from the Bronx Zoo in 2005.

Before pristine skeletons are boxed and cataloged, they are soaked in water and frozen for several days to eliminate any residual beetles and eggs.

Beetles pose no threat to humans, but an infestation within the museum’s specimen collection is undesirable. A sufficient quantity of beetles means strips of petrolatum jelly at the top of the box and sticky patches on the room’s doorway.

If the supply of specimens falls short, Pascocello will resort to chicken as an emergency food source. Sweet mentioned providing the colony with pig feet during the pandemic, as it was the least expensive meat available at the supermarket.

The beetle’s voracious appetite serves as a reminder that significant scientific work doesn’t always happen in spotless laboratories. Above the door, beneath the “Bug Colony” sign, a handwritten note reads:

“The unpleasant odor emanating from behind this door is perfectly normal.”