What are the bugs that start coming into our cottage when the weather gets cooler? They look like some kind of brown beetle. When crushed, they smell like freshly cut grass.
Despite your description, no expert we called was willing to slap a firm label on these mystery bugs. (One just laughed and then hung up the phone.)
“There are 8,000 species of beetles in Canada, and lots of them will come inside in the fall,” says Bob Anderson, an entomologist at the Canadian Museum of Nature.
Without a specimen, a photo, or more info (size, your geographical area, etc.), it’s impossible to i.d. them. However, two potential species spring to Anderson’s mind: the strawberry root weevil—about half a centimetre long, with elbowed antennae—and the June bug—about one to two centimetres long, with clubbed antennae.
If the bugs stink, another culprit could be, well, stink bugs, says Glen Robertson of Robertson’s Pest Management in Coldwater, Ont. There are several species; many are brown and at least one is known for coming inside when the weather turns chilly. They get their name from the odour that they release—usually likened to cilantro—when threatened or squished. (Note: The fact that you think your bugs smell like grass doesn’t mean they’re not stink bugs. According to reports, stink bugs can also smell like rotten cheese, dirty socks, citrus, rubber, air freshener, bananas, skunk, cucumber, tung oil, cinnamon, cat pee, and green apple Jolly Ranchers.)
If the bugs aren’t bothering you, it may not matter what kind they are. Adult beetles will come indoors in the fall because they’re looking for shelter to overwinter. Once they’re inside, they stay active instead of hibernating, because of the warm temperatures. But most won’t bite, go after your food, or reproduce. “They shouldn’t cause any damage,” says Anderson. And they may just die naturally over the winter or leave come spring. “Otherwise,” he adds, “they’ll encoun-ter someone’s foot.”