Most of us are aware that rats, mice, and other rodents are carriers of diseases and infections that are transmittable to humans. But some may not understand that these rats and rodents can spread diseases without even coming into direct contact with us, how that process works, and the infestation signs that are important to watch for. 

Various diseases and dangerous bacteria are abundant in rodent saliva and also in the waste material that they leave behind, such as feces and urine. Clearly, coming into direct contact with these substances, beyond the general grossness of it, poses a risk.

According to the Centers for Disease Control and Prevention (CDC), rats and mice spread more than 35 diseases in various regions around the world.

“These diseases can be spread to humans directly, through handling of rodents, through contact with rodent feces, urine, or saliva, or through rodent bites,” writes the CDC.

This is why it is important to take immediate action by calling an exterminator when there are signs of a rat or rodent infestation

Let’s take a look at the indirect ways rats, mice, and rodents can spread diseases to us, the specific illnesses they can cause, and the signs of an infestation.

Indirect Ways Rats and Mice Spread Diseases

When rodents live in your house, their feces will inevitably begin to accumulate where they dwell, like cabinets and pantries. Fecal matter can easily contaminate stored food and cause medical issues to humans and pets.

Additionally, as rat and mouse feces begin to dry, it can produce airborne particles that can circulate throughout our homes, spreading potentially devastating viruses and bacteria to anyone who inhales them.

Another indirect way that diseases from rats are spread is by other uninvited carriers, such as fleas, mites, and ticks. When these pests come into contact with the bacteria from rodents, by either feeding on the feces or the rat themselves, they then can become a carrier and can pass diseases on to you, your family, and pets, making the household severely sick.

Common Diseases Rats Carry

Now that we have covered the disgusting ways rodents spread illness-causing bacteria, let’s dig a little deeper and take a look at the common diseases rats and other unpleasant animals carry and how they are spread.


These are a variety of viruses that can lead to a potentially deadly respiratory disease, Hantavirus Pulmonary Syndrome (HPS). Hantaviruses live in the salvia, urine, and feces of common North American mice and rats: the deer mouse, the white-footed mouse, the rice rat, and the cotton rat, among other rodent species.

Humans can contract HPS through direct contact with rodents or their waste material. The disease is also transmissible through airborne particles of dried rat waste and fluid, like saliva, urine, and droppings. Symptoms include chills, fatigue, nausea, and abdominal pain, among others.


Children and dogs are most at risk from this bacterial infection, which can be carried without any symptoms and then passed on to the family, causing serious illness. Leptospirosis can be spread through open sores, flea or tick bites, and by water contamination (a rat sharing your dog’s bowl of water, for example).

When symptoms are present, they include vomiting, jaundice, red eyes, bleeding disorders, and other horrifying indicators.  


This is a type of bacterial food poisoning that is spread by rodent feces that causes fever, stomach cramps, and diarrhea, and it infects approximately 1.35 million people a year. Humans are particularly susceptible to salmonella infection as a result of the consumption of contaminated food.

Rat-Bite Fever

Also known as RBF, this disease can be passed on to humans who have been bitten by an infected rodent, weasel, or cat, and can lead to death when untreated. Occasionally, RBF can spread by consuming contaminated food or milk products. Symptoms of RBF include fever, vomiting, muscle ache, and tender, swollen joints.


No, it is not the turn of the 20th century, but rodents still carry plagues that we can catch from flea, tick, and rodent bites. There are three forms of plague: bubonic, septicemic, and pneumonic. Symptoms include fever, low blood pressure, chest pain, shortness of breath, and tender lymph glands, among others. Thanks to advances in modern medicine, these can now easily be treated with medication like antibiotics, though it is better to avoid them altogether.

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Other Dangers Caused by Rats and Other Rodents

Beyond rats carrying diseases, rodent infestations present a significant risk for house fires. Rodents chew straight through the electrical wiring in walls and attics, leading to 25% of the house fires in the United States each year. Mice and rats also gnaw on the electrical wiring in vehicles, like real-life gremlins.

Five Common Signs of Mice or Rat Infestations

You may not actually ever see rodents if they are present in your home, unless there is a severe infestation. However, you certainly want to take action before these rodents become visible to prevent the spread of diseases.

Below are the most common signs of your home becoming a hotel to these unwanted guests.

  • Feces in drawers or cabinets, around food items, and under the sink.
  • Food packaging has chew marks.
  • Nesting items—torn fabric, paper, or dried plant matter—in attics, lofts, or under eaves.
  • Holes with chew marks in walls and floors.
  • Musty odors coming from obscure areas.

How to Prevent Infestations from Rats and Mice

The best way to stop a rodent infestation is to prevent one before it starts with a home exclusion service to seal holes and assist with other infestation issues.

Below are a few other tips to help prevent rodents from calling your home, well, home, so that you can avoid contracting diseases that rats and mice carry.

  • Keep a clean home, picking up food and water in and near your property.
    • Store food in thick containers with airtight lids.
    • Wipe up spills right away.
    • Wash dishes and utensils immediately after use or rinse them and put them in the dishwasher.
  • Use garbage bins both inside and outside the home that have thick, sealed lids.
  • Store pet food in sealed containers.
    • Avoid leaving pet bowls for food or water out overnight.
    • Keep birdfeeders away from the home, using squirrel guards to restrict access.
  • Set traps to catch rats and mice early on.
  • Look into extermination services to avoid rampant infestation.

Contact Life After Bugs

Keep your family safe from the dangerous diseases carried by rats and mice with regular pest and rodent control service. Our family-owned company serves residential and commercial customers in Katy, Richmond, Fulshear, and West Houston. Call (281) 909-6104 or send us an email to request service today.