Scientists are releasing around one million mosquitoes across Hawaii every single week in what could be one of the most unusual conservation efforts ever attempted. But before alarm sets in, there’s an important detail: these mosquitoes do not bite. They are all male, lab-bred, and carry a naturally occurring bacteria called Wolbachia that prevents successful reproduction.

When these modified males mate with wild females, the eggs do not hatch, gradually reducing the mosquito population over time. The goal is to curb the spread of avian malaria, a deadly disease devastating Hawaii’s native honeycreepers. Once numbering more than 50 species, only 17 remain today, with some populations now down to fewer than 100 birds in the wild.

For generations, these birds survived in cooler, high-altitude forests where mosquitoes could not thrive. However, climate change has allowed mosquitoes to move higher into these refuges, removing their last safe habitat. The current strategy involves overwhelming wild populations with sterile or incompatible males in a carefully controlled ratio, reducing reproduction rates without harming other wildlife.

The insects are released using drones and helicopters, often in biodegradable pods containing about 1,000 mosquitoes each, dropped into remote forests on Maui and Kauai. Since late 2023, tens of millions have already been released as part of this ongoing effort. Scientists say the project could become a global model for protecting endangered species from disease if it continues to show success.