Swarms of uncharacteristically large mosquitoes have overtaken North Carolina in the wake of Hurricane Florence, USA Today reports.

North Carolina State University entomologist Michael Waldvogel told the outlet that the large insects, called “gallinippers” or “Psorophora ciliata,” can be three times as large as average mosquitoes.

Severe flooding caused by Hurricane Florence apparently caused dormant gallinipper eggs to hatch, swelling the population of the blood-thirsty parasites into the billions.