Mosquito season should be winding down, but Indian summer may make complacency on this score dangerous, and the Valley is full of microclimates: the temperature differential between a house in the Hilltowns and a suburban home near the Connecticut border may be 10 degrees or more on some days. If it's a warm day, especially during or just after a damp spell, wear clothing that covers and use insect repellent, just as you do to avoid ticks.

Since the mosquito menace won't end with this year's season, get into the habit of keeping your screens repaired, and block other apertures through which mosquitoes can enter your house. Don't let water stand in anything on your property: birdbaths, empty garden containers, flowerpots, or children's playthings such as pails and wagons. There are products (such as Mosquito Dunk) and devices that prevent mosquitoes from growing in water in rain barrels.

If you find a dead bird on your property, don't dispose of it with your bare hands. Use plastic gloves and put it in a plastic bag, then wash your hands. Two hundred species of birds nationwide have been found to be infected with West Nile virus. The state Department of Public Health is no longer asking people to report dead birds, however, because they have other ways of tracking the progress of the virus.

Prevention is doubly important for EEE and West Nile virus because at present there are no vaccines and no cures for them, though there are vaccines whose makers claim that they protect horses from both these diseases. For more information on mosquito-borne diseases and how to avoid them, visit www.mass.gov/eohhs/gov/departments/dph/.