The most common ant in Minnesota is arguably the carpenter ant. These are large black or red ants that bore through moist wood to nest inside of it. For this reason, homeowners most often find them around tubs and sinks, in the attic, and in structural beams that are surrounded by damp soil.
One sign of carpenter ant infestation is when you see piles of sawdust under wood structures. Wood that has been chewed through will have long lines with a smooth, sandpapered appearance, which are called galleries (carpenter ants chew both with and against the grain). You might also see them around your kitchen since they have a sweet tooth. Foraging is usually done in the spring and summer. Indoor nests have been known to survive in the winter.
Centipedes are a common moisture-dwelling insect, the most pervasive being the house centipede. These don’t have 100 legs like other types but more around 30, and they can grow to above an inch long. Their color ranges from grayish yellow to brown. Centipedes prefer dark, moist hiding places, typically entering a home through the foundation, doors, and windowsills. You might find them in the autumn, as they seek shelter from the winter, or in the spring, as they emerge from those shelters. When centipedes bite, they inject a paralyzing venom; in humans, the bitten area will become numb and inflamed.
Millipedes prefer damp places as well, entering homes and hiding in basements and sheds not just before the winter but also after rainstorms. They are black or brown in color, and their legs are much shorter than those of the house centipede. In very bad cases of infestation, you might wake up to find dozens of them squatting on your porch. They don’t bite, but when frightened they secrete a toxin that can cause irritation and even burns on human skin.
Plenty of homeowners know what it’s like to harbor rats and mice in their home. To get rid of them, it isn’t enough to lay down mousetraps because these rodents enter through holes and cracks, usually in the roof or the basement. Patch up the holes first and then look for the telltale signs of rodent infestation: pellet-like droppings, urine stains with an ammonia stench, gnawed wood, tiny footprints in the dust, and scuttling noises in the night.
Rats are known to carry viruses like hantavirus, which infects humans who come into contact with rat urine, feces, or saliva and can lead to hantavirus cardiopulmonary syndrome: a potentially life-threatening disease. Mice, too, can carry plague and salmonella, among other diseases. When cornered, these rodents will bite, increasing your chance of contracting a disease.