Banks aren´t handling their foreclosed properties very well, according to an American Banker story that ran this week (disclosure: I wrote it). That phenomenon is keeping prices down, sure, but there´s another widespread consequence to having so many poorly managed real estate-owned properties around. This one´s-well-itchier.

Mosquitoes have been breeding all year in the still-full swimming pools of foreclosed houses from Florida to California, and the neighbors aren´t happy. Authorities in Destin, Fla., last week ordered Wells Fargo to drain the pool attached to a home it owns. The deadline for the bank was yesterday. The Okaloosa County Sherriff´s Office did not respond to BankThink´s request for an update.

Meanwhile, in Phoenix, Maricopa County officials have gotten used to fining banks for not properly maintaining pools attached to houses they own. When the county gets a complaint, it inspects the property, puts a lien on the house, and issues a court date, both of which must be dealt with before the property can be sold again. Banks have to pay the lien and treat the pool to kill the pests.

And this past summer festering pools raised the specter of the mosquito-born West Nile virus; an article by the Associated Press cited three documented human cases in the Central Valley. Farther south, Bakersfield, Calif., saw a 275% increase in West Nile in 2007.

Just one more reason why bankers shouldn´t go into real estate. They apparently make terrible pool boys.