Here’s what you should do right now if you’ve spotted a rat:

1. Don’t Panic, But Don’t Ignore It

It might be tempting to dismiss a single rat sighting as a fluke, especially if it disappears before you can get a good look. But where there’s one rat, there’s usually more—and they multiply fast. A single pair of rats can produce hundreds of offspring in a single year.

Bottom line: One rat = potential infestation. Take it seriously.