The buzz about radioactive wasps at a Cold War-era nuclear site in South Carolina just won’t die. Investigators found “hot” nests inside a nuclear weapons facility in South Carolina, with scientists warning it could be evidence of either a leak or contamination that wasn’t previously detected.

Employees who routinely check radiation levels at the Savannah River Site near Aiken found a wasp nest on July 3 on a post near tanks where liquid nuclear waste is stored.

The hazardous insect abode was located near a set of tanks filled with liquid nuclear waste, although the team didn’t detect any leaks. Instead, experts believe the nest set off Geiger counters through what’s known as “onsite legacy radioactive contamination.