Visitors from all across the country are in the Smokies this week to get a glimpse of the synchronous flashing of the fireflies at Elkmont.
The event happens around this time each year and people from as far away as California come to view it.
It's an eight-day period where the Photinus Carolinus, a firefly species typically only found in the Southern Appalachians, mates in the park.
"The idea of having the entire forest and having them all go in synchronicity is going to be absolutely amazing," said Georgia visitor Pam Wurst.
The fireflies lay eggs in mass at Elkmont. They then end up dying. The eggs they place at Elkmont end up being the same fireflies who will populate the same part of the park two years later.
Park Ranger Caitlin Worth says it's a unique experience.
"The fireflies are probably my favorite special event of the entire year," she said.
If you'd like to see the event, 85 passes go on sale at 10 a.m. each day at Recreation.gov.
The tickets cost $1.50 and are for use the day after they are bought.