How Long Can Mice Live Without Food? Survival Facts for Canadian Homes

How Long Can Mice Live Without Food?

Mice can live only about 2 to 4 days without food, according to estimates from pest control companies, because their fast metabolism burns through their energy reserves quickly. No government or university study measures this exactly, so treat it as a rough range rather than a precise limit. What research does show clearly is how fast a mouse loses weight when it stops eating, which explains why the window is so short.

This question is different from how long mice live in general. If you want to know their natural lifespan, read our guide on how long mice live.

How Long Can a Mouse Survive Without Food in Your Home?

A mouse can survive without food in your home for a few days at most, and the exact time depends on its situation. Pest control sources list the same factors again and again: access to water, the mouse's age and health, the temperature around it and the species. A healthy adult mouse with water nearby lasts longer than a young mouse in a cold, dry space. Warmth may also help: in laboratory research, mice lost less weight while fasting in a warm room than at normal room temperature, likely because they spent less energy keeping their bodies warm.

In a heated Canadian home, though, a mouse almost never has to test this limit, because a home rarely runs completely out of crumbs, pet food or stored food.

Why Mice Burn Through Energy So Fast

Mice burn through energy fast because they are tiny animals with a very high metabolic rate. According to UC IPM, house mice eat up to 20% of their body weight every day, spread over about 200 small meals a night. Researchers writing in Molecular Metabolism found that laboratory mice lost about 14% of their body weight after just 24 hours without food, and called mice "highly susceptible to fasting" compared with humans. A mouse simply does not carry enough fat to go long between meals.

For more on their daily eating rhythm, see our guide on how often mice eat.

How Torpor Helps Mice Save Energy

Torpor helps mice save energy by letting their body temperature drop for a few hours when food runs short. During daily torpor, a mouse's body temperature can fall from about 37°C to around 20 to 25°C, which helps cut the energy it needs to stay alive (Journal of Experimental Biology). Torpor can be triggered by a shortage of food and by cold, and a study in Biology Letters found that house mice that had to work hard to find food were more likely to use it.

Torpor usually buys a mouse hours, not weeks. Some websites claim torpor lets mice go weeks without food, but no scientific source supports that for house mice. It stretches their reserves a little; it does not replace eating.

Do Wild Mice Survive Longer Without Food?

Wild mice do not have a magic ability to fast longer, but they rely on torpor more when winter cuts their food supply. In a study at Heart Lake in the Northwest Territories, deer mice were often found in torpor during winter. House mice take a different route: where they live outdoors, they tend to move into homes in autumn when nights get colder (UC IPM), where heat and food make fasting unnecessary.

How Long Can Mice Live Without Water?

Mice can live without drinking water for as long as their food contains enough moisture, because house mice get most of the water they need from what they eat. That is why there is no reliable number of days for this question: a mouse eating moist food may never need to drink at all.

How Mice Get Water From Food

Mice get water from food, so most of them never need a water dish. UC IPM states plainly that house mice do not need to drink water to survive. The wildlife damage fact sheet from the University of Nebraska explains that, unlike Norway rats and roof rats, house mice can survive with little or no free water and often obtain their water from the food they eat.

When Mice Need to Drink

Mice tend to seek liquids when their food is too dry or when their surroundings are hot or dry, according to UC IPM. A mouse living on dry grain or crackers in a dry basement will look for liquid. Mice also tend to drink readily whenever water is available, and a lack of water or moist food may reduce how much they breed.

Where Mice Find Water in a House

Mice find water in a house wherever moisture collects. Health Canada points to leaky taps, sweating pipes and open drains, and pet water bowls, sink basins and condensation around plumbing can be other easy sources. If you find droppings near these spots, it is a strong sign mice are using them.

Can You Starve Mice Out of Your House?

Starving mice out of your house rarely works, because a mouse needs only about 3 grams of food a day and finds it close to its nest. Even a clean kitchen usually leaves more than enough for a few mice to survive.

Why Crumbs Are Enough

Crumbs are enough because a mouse eats so little. According to the University of Nebraska wildlife damage fact sheet, a single mouse eats only about 3 grams of food per day, and it often stays within an area about 30 feet (about 9 metres) across. UC IPM adds that house mice can survive in very small areas with limited amounts of food, and that good sanitation alone will seldom control them completely. A few crumbs under the toaster or behind the stove can keep a mouse going.

What Mice Eat When the Kitchen Is Clean

Mice that cannot find people food eat almost anything else. UC IPM lists cereals, grasses, roots, seeds and even insect larvae, and mice may also raid pet food, birdseed and grass seed stored in the garage or basement. Our guide on what mice eat covers their full diet.

Will Mice Leave an Empty House?

Mice do not reliably leave an empty house. Mice in a cottage or a home left empty for the winter can often find enough to survive, since they eat so little, need little or no drinking water and shelter in walls, insulation and stored boxes. Before you close up a seasonal property, remove all food, store items in sealed containers and set traps so you do not come back to a larger problem.

Do Mice Die in the Walls?

Mice can die in the walls, mainly when poison bait is used. UC IPM notes that house mice tend to stay within 30 feet of their nest, so mice that eat rodenticide will often die inside the building, which can cause odour or sanitation problems. If that worries you, trapping lets you remove each mouse yourself.

How Do You Cut Off Food and Water to Mice?

Cutting off food and water to mice means storing every food source in containers they cannot chew and fixing the moisture sources around your home. These steps will not kill mice on their own, but they make your home far less inviting and push mice toward your traps.

Food Storage

Food storage is the first step. Health Canada recommends keeping your kitchen clean and storing dry food in metal or glass containers. Mice chew through cardboard boxes and thin plastic bags easily, so move cereal, flour, rice, crackers and snacks into hard containers with tight lids. Wipe counters and sweep floors every night, and check behind and under appliances where crumbs collect.

Pet Food

Pet food is one of the easiest meals for mice. Health Canada recommends storing dry pet food in metal or glass containers, and UC IPM suggests feeding pets only what they will eat in one sitting. Pick up bowls overnight, and keep birdseed in the same kind of sealed container.

Food Waste

Food waste needs to be locked away too. Health Canada advises securing garbage in containers with tight-fitting lids. If you compost, never put fatty or oily food waste, eggs or milk products in the composter, and use a layer of heavy metal mesh between the soil and the bottom of the bin.

Leaks

Leaks give mice a steady water supply. Fix dripping taps, insulate or repair sweating pipes and cover open drains, which Health Canada lists as water sources to eliminate. Empty pet water bowls at night if you have an active mouse problem, and dry out damp basements and crawl spaces where you can.

Entry Points

Entry points let mice reach your food in the first place. Health Canada warns that mice can squeeze through cracks as small as a dime, and UC IPM gives openings as small as 1/4 inch (about 6 mm). Stuff steel wool around pipes before caulking, put metal weather stripping under doors and cover vents with fine metal mesh, as Health Canada recommends. Avoid plugging holes with foam, rubber or wood alone, because mice can gnaw through them (UC IPM). Our guide on finding mouse entry points walks you through a full inspection.

How Do You Use Food Control to Get Rid of Mice?

Food control helps you get rid of mice because, once their usual food is gone, the bait in your traps becomes the easiest meal around. Combine it with trapping and sealing for the best results.

Trap Bait

Trap bait tends to work best when it matches what the mice are already eating, according to UC IPM. Peanut butter is a popular choice, and Health Canada also suggests bacon grease mixed with oats, raisins or gumdrops. Nesting material such as cotton wool or dental floss can also attract mice. Our step-by-step guide on how to set a mouse trap shows you how to bait and set each type.

Trap Placement

Trap placement matters as much as bait. Health Canada recommends setting 1 trap per metre along walls, or 5 to 10 traps per visible mouse hole, and giving mice a warm-up period of 3 to 4 days. Put traps along the routes between their hiding spots and their food, check them every day and reset them in 2 to 3 weeks to catch younger mice. To choose a trap, see our picks for the best mouse trap.

Rodenticide Safety

Rodenticide safety starts with the label. Health Canada says to always look for a Pest Control Products (PCP) number, which shows the product is approved for use in Canada, and to use poisoned baits only with a tamper-proof bait station in areas accessible to children and pets. Commercial class products must be applied by a certified professional. Follow the label exactly.

Droppings Cleanup

Droppings cleanup needs care, because mouse droppings and urine can spread illness. Health Canada advises never sweeping or vacuuming dry droppings, wearing rubber gloves and a dust mask, and dampening droppings with a bleach and water solution before wiping them up. Our guide on how to clean mouse droppings gives the full method.

When to Call a Pest Control Professional

Calling a pest control professional makes sense when you keep seeing mice after a few weeks of trapping, when droppings show up in several rooms or when you cannot find how they get in. A licensed pest control professional can inspect your home, seal entry points and set up a removal plan. Start with our full guide on how to get rid of mice, browse more mouse guides, or get a quote from a recommended local exterminator through Pest Agent's referral form.