https://phys.org/news/2018-07-hollow-trees-host-massive-moth.html

"That's incredible," he whispered, filming the phenomenon inside a giant southern red oak in San Felasco Hammock Preserve State Park. "So many moths!"

In each of Sourakov's observations, the moths oriented themselves toward the top of the tree and away from the light. They roosted silently, each slightly apart from the others. Sourakov saw both male and female moths, but none were mating, and no larvae were feeding nearby or inside the tree, although the immature stages of this moth eat bark and other organic material.