ALBANY, N.Y. — Unmanned drones are helping New York state environmental workers respond to oil spills and discover remote bat hibernation sites.

The Department of Environmental Conservation said Monday they have 22 unmanned aerial vehicles, or drones, deployed around the state. Officials say the low-flying drones have helped the agency monitor and protect the environment.

Drones have already been used to locate an oil spill in a Staten Island wetland and to map an invasive plant across 200 acres (80 hectares) of wetlands in St. Lawrence County.

Workers also used a drone with thermal sensors to detect underground bat hibernation sites last winter in Mineville in northern New York.