The National Heritage Collection is made up of more than 400 historic sites around England, some dating back thousands of years. Now, the BBC reports that a tiny, winged menace is threatening to eat through the cloth-based artifacts under English Heritage’s care.

English Heritage has been keeping tabs on their clothes moth populations since 1997. In the past several years the numbers have doubled, with rising temperatures being one suspected catalyst. The charity has also discovered a new fabric-munching species of moth in their midst: the pale-backed clothes moth. That’s one of a handful of species currently posing a threat to the collections. Amber Xavier-Rowe, head of collections conservation at English Heritage, told the BBC that clothes moths are “a conservator's worst nightmare.” She says, “They can eat through centuries-old carpets, tapestries, and clothes in a matter of months.”

The moths have also been munching on furs, upholstery, and taxidermied animals. Newly hatched larvae can be even more of a nuisance, damaging fabrics with their silk webbing, when they’re not nibbling on them.

The impacts of the moth problem have been felt around England. In 2015, the Natural History Museum in London found a way to hijack the pest’s own biology to slow its reproduction. Female moth pheromone tablets were scattered around the building to lure in males. Any moth who came in contact with the trap was left smelling like a female, which ended up confusing other males around him and wasting precious copulation time. Moth numbers fell by 50 percent following the system’s introduction.

The conservators at English Heritage are considering their options before investing in moth pheromones. From April through August, visitors will be able to pick up a free clothes moth trap from one of the sites included in the National Heritage Collection and report their findings online. Conservation scientists will use the data they gather to track moth patterns and choose the best course of action moving forward.

[h/t BBC]