The Short Answer: Almost Never
Rats and mice can theoretically be infected with the rabies virus — they are mammals, and rabies infects mammals. But in everyday life, the question "Do rats carry rabies?" has a very practical answer: generally lower concern in US surveillance, while unusual circumstances should be assessed professionally.
The US Centers for Disease Control and Prevention (CDC) has stated that small rodents — including rats, mice, hamsters, guinea pigs, gerbils, chipmunks, and squirrels — are almost never found to be infected with rabies, and have not been known to cause rabies in humans in the United States. After decades of surveillance, that record has held.
This is one of the few places in rabies guidance where the answer is genuinely reassuring. It is also the most-asked rodent-bite question in the country, so it is worth understanding why the answer is what it is — and the rare situations where the rule changes.
Why Rats and Mice Almost Never Have Rabies
The biology comes down to body size and survival.
They Usually Die From the Encounter
For a mouse or rat to become rabid, it would have to be bitten by a larger rabid animal — typically a raccoon, fox, skunk, or stray cat — and then live long enough for the virus to replicate, travel along the nerves, and reach the salivary glands. That entire process takes weeks. A rabid raccoon attacking a rat almost always kills the rat outright. The rodent rarely survives long enough to develop transmissible rabies.
The Encounter Itself Is Uncommon
Rabid wildlife tend to lose normal fear responses, but they also tend to be sick and clumsy. They are not efficient mouse hunters in the final stages of disease. Healthy rats and mice are agile and tend to escape sick predators rather than being bitten and surviving.
CDC Surveillance Backs This Up
The CDC has tracked rabies in animals across the US for decades. Small rodents make up an extraordinarily small fraction of rabid animals reported each year, and there is no documented case of a small rodent transmitting rabies to a human in the modern surveillance era. By contrast, raccoons, bats, skunks, and foxes consistently dominate wildlife rabies cases — see our wildlife rabies overview for the species-by-species risk breakdown.
What About Larger Rodents?
This is where the rule starts to change. "Rodent" is a big category. The CDC distinguishes between small rodents (the ones above) and large rodents.
- Groundhogs (woodchucks): the rodent most likely to have rabies in the eastern US. In raccoon rabies regions, groundhogs are sometimes infected via spillover. Bites from groundhogs are typically evaluated for post-exposure prophylaxis.
- Beavers: rare but documented cases of rabies, especially in regions with active raccoon rabies.
- Capybaras: not native to the US but relevant to travellers in South America. Capybara rabies has been documented.
If you are bitten by a groundhog, beaver, or similar large rodent, treat it as a potential exposure and follow standard post-exposure steps. See rabies PEP assessment factors after an animal bite for the assessment framework — the same logic applies to larger rodents.
What If a Rat or Mouse Bites Me?
Rabies is generally a lower concern in this setting, while bacterial infection and tetanus still warrant attention. A clinician or public-health authority can assess unusual circumstances.
Real Risks From a Rodent Bite
- Bacterial infection: the most common complication. Rodent mouths carry bacteria like Streptobacillus moniliformis (rat-bite fever) and various staph and strep species.
- Tetanus: standard tetanus booster guidance applies (within the last 5-10 years, depending on wound severity).
- Hantavirus, leptospirosis, lymphocytic choriomeningitis (LCMV): these are mostly tied to exposure to urine, droppings, or saliva contamination — not the bite itself — but worth knowing about if you handle wild rodents or live with a heavy infestation.
What to Do Immediately
- Wash and flush the wound with soap and running water for about 15 minutes when possible. This is the single most effective infection-prevention step for any animal bite.
- Apply a clean dressing. Watch for redness, swelling, warmth, or pus over the next 1-3 days.
- Check your tetanus shot status. If your last booster was more than 5 years ago and the bite broke the skin, see a clinician about updating it.
- If the bite was from a wild rat (rather than a pet) or you have any signs of infection (fever, joint pain, spreading redness), see a doctor.
For more detailed bite first-aid steps, see our guide on what to do after a bite.
What About Pet Rats, Mice, and Hamsters?
Pet rodents that have always been kept indoors and have not had contact with wild animals are generally considered lower concern for rabies in US surveillance. There is no documented case of pet rodent-to-human rabies transmission in the United States. If your pet rat or mouse bites you, wound care and signs of bacterial infection require attention; a clinician or public-health authority can assess unusual rabies-exposure details.
That said, if the pet rodent was recently acquired and could have been exposed to wildlife (for example, an animal caught in a humane trap and kept), or if it is behaving abnormally — ataxia, paralysis, sudden aggression — talk to a veterinarian.
Comparison: Where Real Rodent-Adjacent Rabies Risk Sits
To put rodent-bite risk in context against other common wildlife questions on this site:
- Rats and mice: no documented human rabies transmission in cited US surveillance; unusual situations still warrant professional assessment. Wound infection is the real concern.
- Squirrels and chipmunks: same category — see do squirrels carry rabies for the full breakdown.
- Opossums: an animal in which rabies is reported uncommonly, partly because of its unusually low body temperature, although not zero — see can opossums get rabies.
- Bats: the highest-risk wildlife encounter in the US, including cases with no visible bite. See what to do after bat exposure.
- Raccoons, skunks, foxes: the highest-volume rabies reservoirs in US wildlife. Any bite from these animals is a potential exposure and warrants medical evaluation.
When to Get Medical Advice After a Rat or Mouse Bite
A clinician or public-health authority can decide whether rabies PEP is indicated. Clinical evaluation is also important for the wound, particularly if any of the following apply.
- The bite is deep, on the hand or face, or bleeding heavily.
- You have not had a tetanus booster in 5 or more years.
- You are immunocompromised, diabetic, or on chemotherapy.
- The wound shows signs of infection within 24-48 hours: redness, swelling, warmth, fever, or pus.
- You develop joint pain, rash, or fever within 1-2 weeks — these are signs of rat-bite fever.
- The rodent was unusually aggressive, behaving abnormally, or could have been exposed to wild animals.
Use the SafeRabies exposure checklist if you want a guided check for your specific situation, or the facility contact finder to locate urgent care nearby.
Part of our animal rabies guide: see the full overview of which animals carry rabies — including which are higher-concern and which almost never spread it.