Rockland County workers will be spending a lot of time around storm drains as they combat mosquitoes in the coming weeks.

Families may spot the teams tossing what looks like chalk into storm drains, which is a method to battle mosquitoes.

"We treat the storm drains, catch basins, graded structures in the road that hold water," says environmental health specialist James Hornberger.

That's because standing water is where they breed, and the chalk is a treatment that slowly dissolves in drains to stop it.

"It releases a chemical that's a growth regulating hormone into the water that limits the ability of a mosquito to breed into an adult mosquito," says Hornberger.

Rockland has more than 50,000 drains, and the county will treat about half of them for mostquitoes.

The Health Department brought a sample of mosquito larvae, which can breed in even the smallest traces of standing water.

"The debris behind people's sheds, they forget is back there, the wheel barrels, the junk tires, the old pots, they don't realize they're holding water, they're breeding mosquitoes," says environmental health specialist Amy Isenberg.

A great line of defense is to keep yards clean, and pools maintained.

Rockland County has a complaint program for homeowners having issues with mosquitoes: 845-364-3173.