Mammoth Cave Lint Bunnies

A NSS volunteer, Paula, scrubs clean a metal handrail along a cave tour trail.

Who would have thought that something as simple as lint could become such a large distraction in a cave environment? We did!

Every year, hundreds of thousands of visitors come to Mammoth Cave National Park to embark on an underground adventure through the world's longest cave system. Little do these visitors know that while they are busy absorbing information on the cave's geology and history, they are also busy shedding little bits of themselves back into the cave in the form of...LINT! Lint from our clothes, hair from our heads, and tiny bits of trash from our pockets silently fall from our bodies and collect in the cave on every tour. Yuck.

What does the lint look like, you ask? Think about the lint traps in your dryer at home. What is collected in the cave is very similar to what you clean out of your dryer after a cycle of clothes.

 

Park Ranger Rick Olson and NSS volunteers pose outside.

Who cares? It is just lint!

Lint is not only a little gross, but it also can negatively impact the delicate cave ecosystem by adding food to an otherwise food poor environment. It is also unsightly and can lead to microbial growth, dissolution of formations, and discolor cave features like rocks, walls, and flowstone. It also impacts cultural resources that are hundreds or thousands of years old because it collects on artifacts causing damage, and obscures historic signatures found along the tour routes.

The park has taken steps to keep the majority of lint off of the cave walls. Along the touring trails inside the cave, the park installed short boards that line the trails that collect the lint before it can settle in the rocks or walls. These are referred to as "lint rails". The lint will also settle into the cracks of the pavers on the trail and form little balls or "lint bunnies" like you might find under your bed at home.

But what happens once the lint is trapped on the rails or pavers?

 

Two NSS volunteers are using HEPA vacuums to remove lint and other debris along the cave tour route.

Lint Bunnies to the Rescue

The Mammoth Cave Restoration Camp, headed by the National Speleological Society (NSS), hosts three weekend camps and one weeklong camp each year. The NSS camp's director and the National Park Service held discussions about what their members could do to help return the cave environement to a more natural state by removing the dirt and lint, while still allowing visitors to experience the amazing cave system. This is where the NSS Lint Bunny story began. Through their annual restoration camps, volunteers known as the Lint Bunnies began work to mitigate the cave lint through extensive cleaning efforts. The group has been in existence for about 12 years and it continues to help keep the cave clean for thousands of visitors each year.

At first, the Lint Bunnies were a small group who used brooms and dustpans to gather lint along trails in the large upper passageways of the historic section of Mammoth Cave. The clean-up would occur once a year during the weeklong Restoration Camp. However, as techniques and equipment were refined, the collection of lint expanded. Now, camp participants can sign up for daily tasks involving lint cleaning. With the improvement of paved trails throughout the cave, the camp has been able to increase the cleanup efforts to five days at a time. To minimize the impact of daily tour schedules, each lint bunny crew is held to a maximum of six individuals.

Using either brooms or HEPA vacuums, the camp volunteers coax the lint bunnies out from hiding. Over the years, the crews have collected approximately 600 pounds of lint and other items left behind from tours. That is a lot of lint!

If you are curious to see how you can help make imporatant impacts like the Dust Bunnies at Mammoth Cave National Park, visit our vounteer website.

 

Two NSS volunteers are using brooms and dust pans to sweep up dirt, debris, and lint along the cave tour route.