Why Do Mice Come Into the House in Summer?

Mice may be adorable in cartoons, but they are not so cute when you find them in your home! Rodents and pests of all sorts carry bacteria, germs, and even harmful diseases, and may be more destructive to your home than you realize.

Mice come into a house in summer to find a food and water supply, to gain relief from the heat, and because winter weather may have caused damage to your home that creates cracks and crevices mice can use for easy access to a home’s interior. Mice may already be in your home but come to the lower, cooler levels during summer, so you may see more mice during summer than you do during winter!

To keep your home free of mice and other pests, note a few questions you might have about these pesky creatures and why they often mistake your home for their own, and how to keep them out of your house for good!

What season do mice come inside?

Never assume that mice infestations in a home are somehow seasonal, that rodents enjoy being outdoors during summer and then come into your home only during winter. Mice, like all other small creatures, need shelter from inclement weather year-round, and this includes protection from rain and extreme heat, as well as bitter cold. Once summertime arrives, heat and hot sunlight may make your home’s cool basement or the shady areas of your home’s subfloors very attractive to mice.

Mice also need a safe nest for when they are ready to give birth, an available supply of food and water, and protection from predators. Rodents can find all of this in and around your house, at all times of the year!

Note, too, that mice might be more likely to seek shelter inside your home during cold winter months, making their way to the home’s warm attic or crawlspaces. Then, once summertime rolls around and these spaces become uncomfortably warm, those mice might make their way to the lower part of your home.

In other words, mice aren’t necessarily coming into your home during summertime, but you suddenly notice them during the warmer months, since they’re now moving to the living areas of the house.

Do mice come inside when it rains?

As with other animals, rodents like to stay warm and dry when it’s raining outside, so it’s not unusual for mice to burrow into a home during heavy rains. If your local area often has wet summers, you may notice more rodents inside your home during this time, only because those mice are looking for a place to stay dry.

It’s also good to remember that mice need a water supply as well as food. You can keep your trash secure throughout the year so that mice aren’t attracted to any food scraps in your rubbish bins, but if your basement or laundry room tends to flood during heavy rains, mice might be drawn to that standing water and then decide to nest somewhere in your home.

Do mice leave the house during the day?

If your home is prone to a rodent infestation, you may spot mice more often in the evening, versus during the middle of the day. This occurrence is because mice are nocturnal creatures and tend to be active at night versus daytime hours. Mice also don’t like bright lights so that they may avoid rooms in the home with lots of daylight, but then scamper across those same rooms once the sun sets.

Since mice don’t like bright lights, seeing a mouse during the day, and especially in a room with lots of light, might indicate that your home has a large infestation. Those mice you’re seeing may need to leave their cozy, dark nest to find food, so they venture out during the day, even though this is not their favorite time to be active! Their nest may have also been disturbed, so they are moving from one area of the home to another.

Can mice just disappear?

Rodents tend to create nests and then stay in those nests for as long as possible; however, as said, rodents need a steady supply of food and water and protection from predators. If the food and water that mice are finding in your house run out, or if your cat or dog discovers the presence of these rodents, those mice might leave your home on their own.

Mice may also go from one spot to another if their current nest becomes uncomfortable for them for some reason. As an example, rodents may burrow into your home during summertime to get relief from the heat, but if you tend to keep your house very cool during wintertime, those mice might then leave in search of a more comfortable environment.

While rodents can leave on their own for all these reasons, it’s never good to assume that this will happen, even if you start paying better attention to your home’s trash, or if you get your flooded basement cleaned up and repaired. Mice may still find food and water supplies in your home and see that their nest is quite comfortable, so it’s always recommended that you call an exterminator or pest control specialist if you suspect that you have a rodent infestation in your home.

How to find out where mice are getting in your house

Even if you keep your home scrupulously clean, mice and other pests may still find their way inside to get shelter from outside weather, as mentioned. This risk is why it’s vital to find out where mice are getting in your house so you can close up those openings, and make your home far less welcoming and accessible for these pests!

A pest control expert is the best person to call for determining how and where mice are getting in your house, but you can often do a quick scan of your home’s exterior yourself as well. Note any cracks you have along the foundation, basement windows, siding, or brick. These openings should be plugged up immediately, to keep out mice as well as to protect your home from water damage, termites, and other risks to your property!

You can also note areas where your home’s exterior has been drilled for wires and cables. These holes should be tiny and should fit those wires and cables snugly, but over the years, they may have worn away and become more substantial. Remember that mice are small, especially when they’re young; if you can slide a finger through the holes that have been drilled into your home, this often indicates those holes are big enough for mice to get through.

How to keep mice out of the home

Since mice are attracted to food and water sources, one of the best things you can do to keep pesky rodents out of your home is to contain your trash, and this means inside the house as well as outside:

• In the kitchen, use a covered trash bin so that garbage odors are contained, and take your trash bags out regularly so that you don’t have rotting leftovers in the kitchen.
• Mice are also attracted to food that is elsewhere in the home, so be sure you keep bags of pet food or other items you might buy in bulk stored in bins or thick, zipper-sealed plastic bags.
• Invest in rubber or plastic bins for food items you might keep in the garage, or in any such areas that are more accessible to rodents.
• Do the same for food items in the kitchen; keep bread in a plastic container rather than its sack on the kitchen counter, and put flour, sugar, and other staples in glass or plastic bins, to contain spills that might attract rodents.
• Be sure you wipe down the kitchen counters every night, so there are no food scraps that attract mice and keep the inside of kitchen cabinets, especially the lower cupboards, free of food spills and debris.
• Since rodents and other pests also need a water supply as well as a supply of food, be sure your home doesn’t have plumbing leaks behind walls or under floors.
• If your basement tends to hold standing water, invest in a sump pump to keep the space dry.
• Have exposed concrete walls and floors in the basement covered with a patching compound, to plug leaks that lead to standing water inside the home, and which then attract mice.

When should you call an exterminator for mice?

It’s often good to have your home treated for a potential pest infestation before you notice any signs of pests in and around the house. A pest control expert can use sprays or other deterrents that will ensure your home isn’t bothered by termites, roaches, ants, and rodents, and which will then save you the cost of repairs from the damage done by such pests. However, you might need an exterminator if:

• You see rodents droppings in the kitchen or basement, and if you hear scratching sounds in the kitchen or behind walls, as these sounds typically mean that your house has mice!
• If your pets suddenly seem to be bothered by something behind the walls, or begin paying attention to specific areas of the home, perhaps sitting and watching those spaces attentively or hissing and barking at them, this often means that your four-legged companion has spotted rodents or other pests, and it’s time to call an exterminator.
• It’s also good to call an exterminator if your home has been through a flood or has suffered water damage. Even if you have that flooded or damaged area cleaned up somewhat quickly, that standing water may have attracted mice and other such pests, who may now be in your home.
• An additional sign that your home might have a rodent infestation is if the house suddenly has electrical problems. Rodents like to chew through the rubber covering over electrical wires, which damages those wires and interrupts the electrical circuit. If your home has frequent brownouts or shutdowns of specific circuits, and you’ve ruled out other causes for these issues, call an exterminator and have him or her check for rodents and pests in the home.

Do homemade and humane pest control solutions work?

There are plenty of suggestions on the internet for how to control pests and even rodents in your home with humane solutions, but these are rarely effective. You can use traps that capture mice and rats and allow you to release them into your yard, but note that those pests may make their way back to your home, and especially if they’ve nested inside to give birth.

It’s also worth noting that failing to make your home less welcoming to rodents won’t stop new mice and rats from making their way inside! If you don’t plug up holes along the outside of your home, keep the basement and laundry rooms dry, and store your food supplies properly, you may have a long-running battle with mice who infest your house again and again. A pest control expert can often perform a type of audit of the home, noting what needs to be fixed so that mice have less chance of getting inside, and indicating what you need to do to eliminate their food and water supplies.

Getting a cat may also seem like an obvious solution to a pest control problem, but outdoor cats especially can be an excellent deterrent to mice and rats. Active, outdoor cats will sense mice while they’re still outside your home and either scare them away or trap them, so that those rodents don’t make their way inside. Sometimes even the presence of a cat around the house is enough to keep mice away since they prefer to avoid predators altogether! Even with a cat, however, it’s still good to have your home treated by a pest control expert on a regular basis, to ensure mice don’t make your home their own, no matter the season or time of year.