The recent hot weather and rains could bring on more mosquitoes.
One Michigan mayor is working on ways to control that in his town.
Mosquito control briquettes have been applied to nearly 18,000 catch basins in a Detroit suburb.
Warren says it's the first application of the mosquito repellents this year by public works employees. Another application is scheduled for August.
Mosquitoes can breed in catch basins, tire swings, buckets and anything else that holds standing water.
Warren Mayor James Fouts says the control measures are aimed at protecting residents from West Nile virus and other illnesses that can be contracted from mosquitoes and ticks.
Health officials say most people infected with West Nile virus don't develop symptoms.
Sometimes, though, a mild illness results 1 to 2 weeks after exposure.
Those symptoms can include fever, headache, body aches, skin rash, and swollen lymph nodes.
