Philadelphia-area homes are plagued by rodents, according to new Census data.

The American Housing Survey figures released this month show that 18 percent of households in the Philadelphia-Camden-Wilmington metro area reported having seen mice or rats within the past year.

That figure was the highest in the country, according to a Bloomberg analysis of the data, which was released for 25 of the nation's largest metropolitan areas.

Rodents appeared to be a particularly big problem in the Northeast corridor: In the share of households reporting mice or rat sightings, Philadelphia was followed by the Boston, New York and Washington, D.C., metro areas.

Philadelphia fared better when it came to cockroaches: About 7 percent of metro-area households reported sightings in the past year. That put the region 13th in the Bloomberg analysis.

New Orleans, where 41 percent of households reported roaches, was the most cockroach-plagued city.

Overall, the figures point to a huge number of vermin in the Philadelphia region's households: About 392,000 homes with mice or rats and nearly 164,000 with roaches. And some of each total, likely has both rodents and roaches.