Just when you thought that you were safe from the summer barrage of guests, an uninvited crowd shows up at your house.

They are definitely not the most polite visitors — they weren’t invited and didn’t even knock. Instead, they crawled through the cracks and crevices of your windows and doors, the unscreened attic and wall vents, and even the uncapped chimney to descend on what you thought would be a guest-free fall.

Perhaps you weren’t forceful enough and forgot to put up the “No Trespassing” signs, or neglected to let these invaders know that guests should at least call before showing up.

The western conifer seed bug evidently has no manners. It has arrived unannounced in houses all over the Island and all over the country.

Its name gives many clues to its origin and lifestyle. This bug hails from the Pacific Northwest, but has slowly made its way across the United States. First named and identified in 1910 in California, it was subsequently observed in Iowa in 1956, Wisconsin and Illinois in the 1970s, Minnesota, Michigan and Ontario in the mid 1980s, and by 1990 it had found its way to New York. With its boorish habits, I am sure that it had no problem finding accommodations along the way.

These sizeable brown bugs are true bugs, belonging to the order hemiptera, and measure up to one inch (so they’re big pests in both senses). They are brown in color and most identifiable by their sudden arrival in September and October, their slow, plodding style of walking, the buzzing sound (similar to bumblebees) that they make when they fly, and the presence of a swelling on their hind tibia. This last feature led to the nickname of “leaf-footed bug” and “walkey bug.”

The western conifer seed bug didn’t come to your home for your good hospitality. They likely came to the south side of your house first and then found their way inside because they simply needed a good winter domicile. Invaders, every one of them!

It could be argued that now that they are here, they will be pretty good guests. They definitely won’t eat you out of house and home because they don’t eat at all in the winter — they live off of their fat reserves. Nor will they invite their girlfriends or boyfriends over, since they do not breed in the winter. And they don’t sting, since their proboscis is only good for sucking, not puncturing.

But you know the old saying by Ben Franklin about how guests and fish begin to smell after three days? The worsthabit of these bugs (besides coming over empty-handed) is that they will emit an odor if they are bothered, harassed or squished. This smell has been described as the scent of sour apples, rotting oranges, pine sap and crushed grass. It is not, however, as bad as the stench of the assa ssin or true stink bugs, though it is often confused with both of these species.

So if you find western conifer seed bugs cohabitating with you this winter, do not squash them. Be gentle and simply show them the door (and toss them out of it). Pesticides are not recommended, as they would have to be used inside your house and can thus affect you, your family and your pets. It has been suggested that one can vacuum the bugs up, though the thought of a vacuum bag full of western conifer seed bugs is very unappealing.

These bugs do overstay their welcome, as they are hoping to hang out in your house until May or June. That is when they will go back outside to mate, laying their eggs on the needles and scales of conifer trees and feeding themselves and their young on the cones, sap and pine of these trees. (It seems they are not very good guests to the conifer trees, either.)

The best that you can do to keep them out is to reduce entry points into your home. Caulk cracks and crevasses, screen attic and wall vents, and seal window and door edges.

These harmless houseguests are only temporary visitors that can easily be shown the door. After so many guests, I bet that might sound like an appealing option on occasion. And not only for the bugs!

Suzan Bellincampi is director of the Felix Neck Wildlife Sanctuary in Edgartown.