In a Wednesday afternoon tweet, the U.S. Food and Drug Administration warned that people who are allergic to seafood should keep cicadas off their dinner plates. “Yep, we have to say it!” the agency wrote, noting the giant bugs share a “family relation” to shrimp and lobsters. The notice comes after a monthlong media frenzy over the flying insects, which recently emerged after 17 years underground. Since then, people across the eastern United States have been documenting their appearances as they burrow out of the ground. This isn’t the FDA’s first tweet on consuming cicadas: The Center for Veterinary Medicine has cautioned against eating the critters, saying they could potentially harm the stomach lining and serve as a choking hazard.

“Brood X” cicadas are a periodical species of cicadas, known for their loud mating calls and massive numbers, though they aren’t harmful. They’ve appeared in 15 states along the eastern U.S., along with Washington, D.C.