Why is it in your house — really?

Indian Meal Moths

“The moth doesn't find your cupboard. The eggs are usually already in the bag when you carry it home.”

TravelSecondhand itemsNothing you did

Bed Bugs

“You did not attract bed bugs. You cannot attract bed bugs. A spotless house is exactly as likely to have them as a cluttered one.”

Clothes Moths

“Clothes moths don't fly toward your house looking for wool. The wool arrives with them already on it.”

Secondhand itemsShelter

Brown Dog Ticks

“Brown dog ticks don't come for your house. A dog carries the first one in — but this is the one tick that can then keep going without ever going back outside.”

An animal hostShelter

Black Rats

“You almost certainly do not have a black rat. New Hampshire's rat is the Norway rat — we say ‘not established’ rather than ‘never recorded,’ because a rare cargo-carried specimen can't be ruled out, but it is not what's in your walls.”

TravelNothing you did

Fleas

“Fleas don't come for your house. A host brings them in, and the house just becomes wherever the fleas end up developing afterward.”

An animal host

Drugstore Beetles

“Drugstore beetles don't seek out your kitchen. The product usually gets there first, already carrying them.”

American Dog Ticks

“American dog ticks don't come for your house. They wait in grass and brush for a host, and the host is what brings them the rest of the way.”

Flour Beetles

“Flour beetles can't even break into whole grain on their own. Whatever brought them in had to already be milled, damaged, or dusty — and already infested.”

TravelSecondhand itemsNothing you did

Brown Recluse Spiders

“You almost certainly haven't found a brown recluse. New Hampshire is outside its range — we say ‘not established’ rather than ‘never recorded,’ because a rare carried-in specimen can't be ruled out, but that's the exception, not something the house did.”

Cigarette Beetles

“Cigarette beetles don't go looking for your pantry. The infested product usually gets there first, and the beetle is already inside it.”

Deer Ticks

“Deer ticks don't come for your house. They wait at the woods' edge for a host, and a host is what closes the rest of the distance.”

Dog Ticks

“Dog ticks don't come for your house. A dog picks them up outside, and that's what brings them the rest of the way in.”

Lone Star Ticks

“Lone star ticks hunt hosts, not houses. Whatever they attach to outdoors is what brings them the rest of the way in.”

Roof Rat

“If you have a rat in New Hampshire, it's a Norway rat, not a roof rat — the roof rat isn't established this far north, and a real one here almost always arrived by cargo, not by choice.”

TravelNothing you did

Sawtoothed Grain Beetles

“This beetle can't fly and isn't drawn to light. If it's in your house, a bag of something carried it there — nothing else could have.”

Spider Beetles

“This one usually isn't about your groceries at all. It's about debris and old nests that may have been part of the building longer than the food was.”

FoodShelter

The belief is wrong

the common answer is counterfactual

Cluster Fly

“It was never your garbage. The whole life cycle happens in the soil, on earthworms — the attic is just where they wait out winter.”

Boxelder Bugs

“It isn't food or water indoors. It's a female boxelder tree nearby, and a sunny wall to gather on before the cold sets in.”

Brown Marmorated Stink Bugs

“It isn't your furnace. This bug just wants a dry, tight crack to wait out the winter — your house works as well as a dead tree would.”

Asian Lady Beetles

“It isn't your porch light, and it isn't heat coming off the wall. It's the contrast — a dark line against a light one — that tells the beetle where to land.”

WarmthShelter

Western Conifer Seed Bugs

“It isn't warmth from the house. It's whichever pine or spruce is planted next to it — that's what predicts which house gets found.”