Halloween conjures frightening images of bats emerging from dark caves looking for human blood. In reality, as the trick-or-treating begins, bats are settling into caves where they’ll hibernate for the winter and face something far scarier.

White Nose Syndrome, a deadly disease caused by the fungus Geomyces destructans, affects hibernating bats and has killed more than 5.5 million across 19 states since 2006.

Currently, there is no way to treat the devastating disease, which typically causes 90 percent-plus mortality three years after it appears in a bat cave. Although several chemicals can kill the fungus, we can’t unleash them in a cave because they would kill numerous other organisms living there.

But why are bats so important? Insects.

Bats are the top consumer of night-flying insects. A colony of only 150 bats can eat more than 1.3 million insects a year. Imagine how many insects a colony of 200,000 could consume.

Acting as a natural pest control, bats prevent crop damage and reduce the amount of chemical pesticides farmers need to use. Studies estimate this free pest control has a $313 million economic impact in Tennessee, where agriculture is one of the top industries and generates $3.1 billion annually. Bats have an estimated economic impact of $3.7 to $53 billion annually in the United States as a whole.

In an effort to curb the damage caused by White Nose Syndrome, The Nature Conservancy, in partnership with the Tennessee Wildlife Resources Agency and local construction firms, built the world’s first artificial hibernation cave. Located near a natural cave with a population of about 265,000 bats in Clarksville, the artificial cave is about the size of a single-wide trailer home, measuring 78 feet long, 16 feet wide and 11 feet tall, and can hold up to 200,000 bats. The cave will provide a fungus-free environment and can be disinfected every summer without concern for other organisms.

We have no guarantee the artificial cave will work. Bats may not like it — though they often adopt man-made structures as homes. Or we may not be able to stop the fungus from killing bats even if they do use the cave. Nevertheless, the top bat experts we consulted believe our cave has a good chance of succeeding.

If the cave can attract a high volume of bats and remain a fungus-free environment, artificial caves may be the best defense against White Nose Syndrome, something The Nature Conservancy kept in mind when creating the $300,000 structure. To make the cave easy to duplicate, it’s been designed to be simple and affordable to assemble. And it can be replicated almost anywhere.

So when you see bats in all their Halloween glory, remember they face a critical struggle against a disease much more frightening than any horror movie. They need our help and we need them.

Cory Holliday directs the cave and karst program for The Nature Conservancy in Tennessee and has been a part of the organization since 2004.