Motorists are asked to watch for slow-moving vehicles as the annual dropping of larvicide pellets into street drains begins this week.
The vehicles used have a flashing yellow rooftop light, West Nile virus signs and a "Makes Frequent Stops" caution sign.
The program is designed to control mosquito larvae and reduce the incidence of West Nile virus in Sarnia-Lambton.
To eliminate other potential mosquito breeding sites, Lambton Public Health encourages residents to remove stagnant water from around their property.
They are also asked to report all dead birds sightings by calling 519-383-3824, or online at www.lambtonhealth.on.ca.
Mosquito trap surveillance begins in early July and positive tests will be reported.