Common fall pests such as cluster flies are infamous attic dwellers in the colder months. Also known as attic flies, cluster flies creep in during the fall to find a new, warm home to call their own.

Particularly on sunny winter days, these pests will migrate into direct sunlight on windows. However, they may also live inside the walls where they’re unseen. This situation can bring on more issues if they die in the walls, attracting more insects to them.

Because they can fit into the smallest spaces, like electrical outlets or baseboards, cluster flies find their way into your home through incredibly small holes.

Although ladybugs are traditionally perceived as a sign of good luck, seeing ladybugs in your home doesn’t emit the same feeling. This fall pest is actually a ladybug variant called the Asian lady beetle, which was introduced to the United States for other pest control purposes.

These pests reside in high-up places — under siding and shingles and in attics, porches and garages. When they begin appearing, they come in hundreds. Typically, Asian lady beetles leave evidence of their presence in spotting on walls and can exude a foul-smelling defensive chemical if you squash them.

Most Americans are familiar with the brown marmorated stink bug, as it’s present in at least 41 states. These insects begin appearing in and around houses when people clear the fields they’re living in or the plants they call home wither from the cold.

Like many other fall pests, their motive for invading your house is to seek warmth, and they cling to window screens and make homes hidden in personal belongings. Before bringing in items from outside — or even from your car — you should check inside to see if a brown marmorated stink bug is hiding inside.

If you squash a stink bug, it’ll emit a foul odor — and doing so with your bare hand can produce dermatitis at the point of contact.

Though year-long inhabitants of many homes, spiders tend to make an appearance most in the cooler months. Because spiders mate in the fall, they’re trying to lay as many eggs as they can before they die. Female spiders can lay up to 100 eggs simultaneously when living indoors, which means an infestation can happen quickly if you don’t notice them.

It may seem like spiders want shelter when they invade our homes, but they actually want a reliable source of food. Killing a spider is an effective way to maintain control over their population. If you begin spotting a plethora of spiders indoors in the fall, the problem will only get worse as they continue to live, breed and hatch. It’s important to contact a professional in this situation.

Though wasps are typically thought to be aggressive in the summer, they’re even more angry and dangerous in the fall. As they begin to prepare their queen and hives for winter, their defensive behavior only grows when the cold sets in. As their food sources become depleted when flowers and smaller insects die off, they adjust their diets to foods high in sugar and carbohydrates to better sustain themselves — hence, wasps crawling into soda cans.

These common fall pests build their nests in the walls and ceilings of your house for warmth. This situation can cause more damage than many homeowners realize. Sometimes, wasp infestations can require exterminators to do a nest extraction by cutting their wall or ceiling open, which can be a costly experience.