Warning Signs Of A Roof Rat Problem (And Crucial Preventative Measures To Take)

No one likes uninvited guests — especially the kind that move in full-time and never pay rent. That's exactly what roof rats do. These small rodents, between six and eight inches long, look a lot like their rat relatives. But they're sleeker, with black or brown fur, a pointed nose, big ears, and their signature long, hairless tail, and unlike their street-savvy rat cousins who might infest your backyard, roof rats prefer the high life — literally. They tend to nest in attics, garage storage spaces, rafters, roofs, and even inside walls.

So how do you know if you have a roof rat problem? Hunker spoke with Ben Hottel, an entomologist at Orkin, in an exclusive interview, to get some answers. He shared how to spot the signs of an infestation, the best ways to get rid of these unwelcome guests, and most importantly, how to keep them from coming in. As he explained, "They tend to use utility lines and tree branches as bridges to enter homes, rather than scurrying across the ground."

And there are good reasons why you don't want them settling in. "Roof rats and other rodent species can be carriers of a variety of diseases," Hottel warned, and he listed the examples of rat-bite fever (which you can contract through a bite or even contact with a dead rat), salmonellosis (which spreads through food or water contaminated by rat feces), and leptospirosis (a disease transmitted when rats eat and contaminate stored food in your pantry). Ready to evict these tiny squatters? Here are his expert recommendations. 

There are three main warning signs that you may have a roof rat infestation. First, as highlighted by Orkin entomologist Ben Hottel, check for droppings. He explains that roof rat droppings are about half an inch long with pointed ends. "If you find these droppings around your home, especially in your attic or rafters, you may be facing a roof rat issue.

Another telltale sign? Grease marks. "Unexplained grease marks across surfaces in your home can be a sign of a roof rat infestation," Hottel says. "These marks come from oils in their fur as they travel along baseboards and other surfaces." So if you see weird unexplained grease marks along surfaces, it might be a sign to go looking for droppings. Which leads us to the final, most obvious, and most alarming sign of all: Spotting the rats themselves. Whether dead or alive, even a single sighting shouldn't be ignored. As Hottel warns, "If you see roof rats in your home, it often indicates there are hiding spaces filled by other rodents." 

If you go searching for their nests, start in the attic, loft, or inside walls. According to Hottel, roof rats prefer to nest indoors in well-insulated areas, building their homes with shredded materials like paper, cloth, and cardboard.

Okay, so you have now identified a roof rat problem. Now what? As with any rodent issue, calling a professional pest control provider is essential for tackling roof rats: An infestation is not something to take lightly, but professionals can create a targeted treatment plan to resolve the issue effectively.

To prevent roof rats from coming in at all, though, homeowners can take preventative measures. The first step is to seal up any potential entry points, as Orkin entomologist Ben Hottel explained in our exclusive interview, because they don't need a lot of space to get in. "Roof rats can squeeze through holes as small as a quarter. Ensure there are no gaps in exterior doors and check that utility line access points are properly sealed." For example, homeowners can install screens on vents can also help keep these pests out. However, Hottel cautioned that doing so can be dangerous for untrained homeowners, so it may be best to leave this step to the professionals. 

Another often-overlooked tip? Trim back tree branches. Since roof rats use branches as bridges to access your home, cutting them back can help stop them from getting inside, Hottel explained. And finally, eliminate potential food sources to keep them away. This means securing garbage bins, picking up fallen fruit or nuts from the ground, and making sure your home compost is rodent-proof. By taking these steps, you can keep roof rats out of your yard and away from your house, which should prevent them from ever moving in.