Hidden Health Risks of Rodent Exposure in California

Can You Get Sick from a Rat Infested House?

Yes, living in a rat‑infested house can make people sick due to exposure to diseases spread through rodent droppings, urine, saliva, and airborne particles. Hearing scratching in your walls or finding droppings in your home can be alarming, and while rats and mice are both dangerous, rats typically pose a greater risk due to their size, larger colonies, and the amount of damage they cause. Both rodents carry diseases that can impact human health, making prompt removal essential. Hantavirus infections have been linked to rodent exposure in residential settings, highlighting the serious health risks associated with infestations.

What Rat Diseases Are in California?

Rats in California can carry diseases such as hantavirus, leptospirosis, salmonella, rat bite fever, and lymphocytic choriomeningitis. When you hear “rat disease,” the first thing that comes to mind may be the bubonic plague, but that’s certainly not the most common illness carried by these animals. While the plague is still around, it’s rare, and there are some other rodent-borne illnesses that are of higher concern.

Hantavirus: Hantavirus is found in the droppings, urine, and saliva of rats and mice, so you might think that you have to interact with them to get sick, but this is not the case. Hantavirus can travel on tiny particles of dust, infecting people by entering their lungs.
Lymphocytic Choriomeningitis (LCMV): This disease is actually associated with house mice, and causes headache, nausea, and fever. It is spread by exposure to rodent droppings and nesting materials, and in some cases, it can cause severe neurological symptoms.
Leptospirosis: This is type of bacteria that lives in rat urine, and as they move through your home, rats leave smears of urine behind that may be infected.
Salmonella: You might think of salmonella as a foodborne illness, and indeed it is. Rats spread it by infesting a kitchen, leaving droppings in the pantry and on the counters. The bacterium in the droppings contaminates food and can make people very sick, with vomiting, diarrhea, and a fever. People with weakened immune systems, as well as the very young and the very old, are most susceptible to salmonella, and can be severely affected.
Rat Bite Fever: It may sound like a disease that requires a rat bite to spread. This is not quite correct, though, as rat urine or droppings in food or water can also transmit this disease.

Hidden Health Risks of Rodent Exposure

When you think about rodent-borne illnesses, you probably think about coming into direct contact with rodents or their bodily fluids. Being bitten or scratched can transmit diseases, and when rodents infest your food, they leave behind bacteria like salmonella. However, it’s not always that straightforward. As is the case with hantavirus, many rodent associated diseases can contaminate dust particles, infecting people through airborne transmission. In fact, just by sweeping or vacuuming a room where rodents with hantavirus have been present, you can send those particles flying into the air, where you will inhale them if you’re not wearing protective gear. Additionally, rats often have fleas and ticks, and these parasites can spread to humans and pets, carrying with them rat-borne diseases, as well as flea and tick-borne diseases like Lyme disease. Beyond infections, rodent dander and droppings can worsen asthma, and can trigger allergic reactions. Finally, rodents can endanger your family by chewing on wires and increasing the risk of a house fire.

Does California Have a Rodent Problem?

California definitely has a rat problem, and it seems to be getting worse. Each year, our industry releases the “Rattiest Cities in America” list, and in 2025, California was the most represented state on the list, with four cities in the top 25 and two in the top five. Los Angeles took the top spot, displacing Chicago, which had been America’s rattiest city for a decade. San Francisco is number four, Sacramento number 19, and San Diego number 24.

What Are the First Symptoms of Hantavirus?

Early hantavirus symptoms include fever, fatigue, muscle aches, headaches, dizziness, and abdominal pain, followed by respiratory issues in severe cases. Hantavirus doesn’t present with symptoms right away. It takes one to eight weeks after contact with an infected rodent to show early signs like fatigue, muscle aches, and fever. About half of all people with hantavirus also experience headaches, chills, dizziness, and abdominal pain. Later, patients are likely to have symptoms like coughing and shortness of breath.

What Illnesses Can You Get from Rodent Droppings?

Since hantavirus was first identified in 1993, it has been connected to 60 deaths and more than 70 illnesses in the United States alone. It’s not the only illness that is spread through rodent droppings, though. Leptospirosis is caused by bacteria that survives for a long time in water, so people who live in areas where rodents are prevalent are at high risk of contracting this illness.

Why Immediate Rodent Removal Matters

Immediate rodent removal reduces health risks, prevents property damage, and lowers the chance of disease transmission inside the home. You may have heard that rats are extremely intelligent, and it’s true. They’re also highly adaptive, but trust us, this is not the kind of genius you want living in your home. Their intelligence makes them wily, however, and it can be difficult to get rid of an infestation. To protect your home and family from the health risks of rats and mice, take action immediately, working with a local pest control company to remove these creatures from your home. The longer rodents remain in your home, the more damage they’ll do, and the higher the risk that you and your family members will contract a rodent-borne disease.

Recent Hantavirus Deaths in California Highlight Growing Public Health Risks

The hantavirus disease has a 38 percent mortality rate, so it’s a serious concern. Most cases of hantavirus occur in Arizona, New Mexico, or California, so residents of those states are advised to be particularly vigilant. Homes and buildings should be sealed to keep rodents out, and every precaution should be taken to avoid contact with rodents and rodent droppings. If it is necessary to clean areas that rodents may inhabit, it’s crucial to use gloves, masks, and disinfectant.

When to Call a Professional

At the first indication of a rodent infestation, call for professional assistance. So, what are the signs of an infestation? Rats leave large droppings, gnaw on hard materials, and leave greasy streaks on walls. Mice are much smaller, so their droppings and gnaw marks are also smaller, and they make little squeaks and soft scratching noises. Rats, on the other hand, make loud scratching and thumping noises that might keep you up at night. Getting rid of a rat infestation is not easy, but pest control professionals can develop a custom strategy that involves baiting, trapping, sealing entryways, and getting rid of water leaks, open food, and crumbs, which may attract rodents.

For Effective Rodent Control, Call MightyMite Termite Services

In the Bay Area, there is no one more experienced in rodent control than MightyMite. At MightyMite, we’ve earned a reputation as experts in California termite control. We perform termite inspections to ensure that your home is free of termites and work hard to help you keep it that way, using termite treatments that are naturally derived, environmentally low-impact solutions. We diagnose and treat infestations with the most effective methods and unmatched warranties, solving your termite problems the first time, with an industry best “no call-back rate.” That, combined with our experience, technology, and highly trained professional staff, makes us the leading extermination company in the Bay Area. We understand that your home is your most important investment, so we work hard to provide excellent service, utilizing best practices to solve our customers’ termite problems. To schedule an inspection or learn more about our services, contact us through our website.