Seeing a mouse scurrying across your kitchen floor is startling enough, but trying to catch it and ending up with a painful bite can be downright terrifying. Mice are naturally very timid creatures that want to avoid humans at all costs. However, if they feel trapped, scared or cornered, they will use their sharp front teeth to defend themselves.

While a mouse bite is usually very small, it should never be ignored. A mouse’s mouth is full of bacteria, and because their teeth are so sharp, they can push those germs deep under your skin. Knowing exactly how to clean the wound and what warning signs to watch for will help you prevent a serious infection and heal quickly.

What’s happening in your body

A mouse has long, incredibly sharp front teeth called incisors. When a mouse bites you, it usually does not leave a wide, open scrape. Instead, it creates a “puncture wound.” This means the tiny teeth poke a deep, narrow hole straight down into your skin.

When the teeth break your skin, they push the bacteria from the mouse’s saliva deep into your tissue. Because the hole is so narrow, your skin often heals and closes up very quickly. Unfortunately, this traps harmful bacteria inside your body, according to Healthline. Your immune system immediately recognizes the invading germs and sends white blood cells to the area to fight them off. This internal battle is what causes the bite area to become red, swollen, hot and painful over the next few days.

Common causes

Mice do not hunt humans, so a bite almost always occurs during a direct physical interaction in which the animal feels its life is in danger.

The most common cause of a mouse bite is homeowners trying to handle pest control on their own. If you try to pick up a wild mouse caught in a live trap, or if you reach your hand into a dark corner where a mouse has built a nest, the frightened animal will bite to escape.

Another common cause involves domestic pet mice. Even a friendly, tame pet mouse can bite if it is startled awake from a deep sleep, if you grab it too tightly or if it mistakes your finger for a piece of food because you smell like a sweet treat.

Mouse bite diagnosis and treatment

If a mouse bites you, your immediate actions at home are actually the most important part of your treatment.

The very first thing you must do is wash the bite. Run warm tap water over the wound, then wash it thoroughly with antibacterial soap for at least five full minutes. This helps flush the dangerous bacteria out of the deep puncture hole before the skin has a chance to close over it. After washing, pat the area dry, apply an over-the-counter antibiotic ointment and cover it with a clean bandage.

If you see a healthcare provider, they will examine the wound to ensure there is no nerve or tendon damage. The Mayo Clinic explains that for deep puncture wounds caused by animals, a medical expert will often prescribe an oral antibiotic (such as amoxicillin) for a few days to aggressively kill any bacteria trapped under the skin and prevent a severe infection.

After getting bitten, your first instinct might be to squeeze the wound hard to force the blood and germs out. You should absolutely avoid squeezing or pressing heavily on the puncture. Squeezing can actually damage your own tissue further and push the mouse’s bacteria deeper into your healthy muscles. Let it bleed naturally for a moment, and then focus entirely on washing it with warm, soapy water.

What is the #1 disease spread by mice?

When people think of mice, they often worry about rabies. However, small rodents such as mice rarely contract rabies and are not known to transmit it to humans, the World Health Organization explains.

The number one disease associated with mice is Hantavirus. However, Hantavirus is generally spread by inhaling dust contaminated with mouse urine and droppings, not through bites, the Cleveland Clinic notes.

When it comes specifically to a bite, the Centers for Disease Control and Prevention (CDC) warns that the primary concern is a bacterial illness called Rat-Bite Fever (RBF). Despite the name, you can absolutely get this disease from a mouse.

If the mouse carries this specific bacteria, it can cause you to develop a high fever, vomiting, muscle pain and a flat red rash on your hands and feet within a few days to a few weeks after the bite.

Do I need a tetanus shot if I get bitten by a mouse?

Yes, you very well might need a tetanus shot. Tetanus is a serious bacterial infection that affects your nervous system and causes painful muscle stiffness.

The bacteria that cause tetanus live in dirt, dust and animal feces, and they thrive in deep, dark puncture wounds where there is no oxygen. Because a mouse bite creates the exact type of deep hole that tetanus loves, your health expert will check your medical records.

The National Institutes of Health (NIH) notes that if it has been more than five to 10 years since your last tetanus booster shot, your doctor will highly recommend that you get a new one immediately to keep you completely safe.

“Avoiding contact with or breathing in aerosolized rodent urine or feces, especially in a poorly ventilated area, is key,” said Dr. Erin Phipps, the state public health veterinarian with the New Mexico Health Department.

When to see a doctor

“While you can clean a minor bite at home, several warning signs require a doctor’s immediate attention,” says Dr. Justus Rabach, MD. “You should see a doctor the same day if the bleeding does not stop after applying firm pressure for 15 minutes, or if the bite is on a joint, your face or your hands.

You must also seek immediate medical care if you develop signs of an infection within a few days. These signs include the bite becoming bright red, feeling hot to the touch, leaking yellow or green pus or suddenly developing a fever, chills or severe muscle aches.”

Bottom line

A mouse bite is a deep puncture wound that can trap dangerous bacteria under your skin, increasing the risk of bacterial infections and diseases such as Rat-Bite Fever. You should immediately wash the wound with soap and water for five minutes, then apply an antibiotic ointment. It is highly recommended to see a doctor promptly to receive a tetanus booster and a prescription for antibiotics to prevent severe health complications.

Frequently Asked Questions

Should I go to the ER for a mouse bite?

You do not usually need the emergency room unless the bleeding will not stop or you have a severe allergic reaction. Still, you should visit an urgent care clinic or your regular doctor promptly for antibiotics and a tetanus shot.

How long does a mouse bite mark last?

If the bite is kept clean and does not become infected, the small puncture wound will usually heal and fade away within a few days to a week.

Citations

Yetman D. What to Do If You’re Bitten by a Mouse. Healthline. Published September 18, 2020. Accessed March 27, 2026. https://www.healthline.com/health/bit-by-a-mouse#risks-and-side-effects

Mayo Clinic. Animal bites: First aid. Mayo Clinic. Published 2017. https://www.mayoclinic.org/first-aid/first-aid-animal-bites/basics/art-20056591

World Health Organization. Rabies. World Health Organization. Published June 5, 2024. https://www.who.int/news-room/fact-sheets/detail/rabies

Cleveland Clinic. Hantavirus Pulmonary Syndrome: Symptoms & Treatment. Cleveland Clinic. Published December 8, 2022. https://my.clevelandclinic.org/health/diseases/17897-hantavirus-pulmonary-syndrome

CDC. About Rat Bite Fever (RBF). Rat-bite Fever (RBF). Published May 2, 2024. https://www.cdc.gov/rat-bite-fever/about/index.html

M. BORELLA-VENTURINI, C. FRASSON, F. PALUAN, et al. Tetanus vaccination, antibody persistence and decennial booster: a serosurvey of university students and at-risk workers. Epidemiology and Infection. 2017;145(9):1757-1762. doi:https://doi.org/10.1017/s0950268817000516

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