Well, it depends. The D.C. Department of Health assigns every food establishment in D.C. a number between one and five—with five for the highest health risk.

Here’s how the system works: An establishment’s number indicates how often health inspectors must visit each year—a restaurant with a “one” gets one visit, and so on. The numbers reflect the kind of food, the number of people served at a time, the complexity of the menu, and the restaurant’s history. So while a high number means an establishment requires more oversight, it doesn’t necessarily mean it’s a health hazard. For example, a seafood distributor is probably a “five,” while a gas station serving wrapped snacks is probably a “one.” Most restaurants are “threes” or “fours.”

Multiple complaints or a closure due to health violations can raise the risk level, requiring more frequent visits. Restaurants in neighborhoods that are known to have rodent problems, like Dupont or Chinatown, might also get more attention from inspectors (though proximity to rats won’t necessarily raise the number).

All inspections are unannounced, except those occurring before the establishment opens. Restaurants are only shut down due to an imminent hazard—such as no water, incorrect food temperatures, sewage back-up, or vermin infestations—or a license issue. If a restaurant cannot address a violation immediately, the health department will shut it down until the problem is fixed, after which point an inspector will return for a reinspection.

The Department of Health closes about four to six places per week, according to food safety manager Robert Sudler. “Half of the places you close are shocked or embarrassed. They obviously don’t ever want it to happen again,” he says. The other half are repeat offenders. “You have some operators where it’s just the routine,” Sudler says. “It’s how they run the place.”

While inspection reports are publicly available, keep in mind that they’re each a snapshot of a restaurant’s health safety. After all, most restaurants are inspected only three times a year. A health inspector might not see signs of mice on a particular day, but the establishment could still have them. Conversely, sometimes a restaurant simply messes up. “They had a bad day. The manager didn’t come in that day,” Sudler says. “It could be anything as to why it got closed on that particular day.”

Be wariest of restaurants whose health reports show repeated problems with food temperatures, rodents, or unwashed hands. Or just use your eyes. Sudler says that, in his experience, the cleanliness of the bathroom is a good indication of what the kitchen is like. Food particles on the tables or lots of trash build-up in the back can indicate rodent problems. “I try to use a little common sense,” Sudler says. “If it doesn’t look right, if it doesn’t smell right, it’s probably not right.”