Crews are spraying on the city's far Southwest and Northwest Sides.
There have been no confirmed human West Nile cases so far this year in the city.
But experts say mosquitoes are more likely to breed when the temperatures remain high at night.
Crews are spraying on the city's far Southwest and Northwest Sides.
There have been no confirmed human West Nile cases so far this year in the city.
But experts say mosquitoes are more likely to breed when the temperatures remain high at night.