Southern Ontario residents are noticing wriggling masses of red and black bugs congregating in their backyards, and even making incursions into homes.

Boxelder bugs are alarming-looking creepy crawlies that, despite their menacing appearance and dense swarms, are little more than a nuisance to us humans.

This North American native species of true bug, as their name implies, subsists primarily on developing seeds of boxelder trees, but will also readily snack on maple and ash trees.

When fully mature, they measure about 13 millimetres or half an inch long, defined by their dark brown or black bodies with red wing veins and abdominal markings.

They're from the same family as stink bugs and cicadas, but luckily, not anywhere near as smelly or noisy as their distant cousins on the evolutionary chain.

So, why do they swarm?

They're not doing it to stay warm as much as they're just doing it.

Yes, that's right. Those swarms of black and red bugs are actually disgusting mass "breeding orgies" with entirely too many legs in the mix.

what is this bug and is it invasive to ontario canada?
byu/grindylin inwhatisthisbug

Boxelder bugs typically emerge in spring and appear in greater abundance during hot, dry, summers, sticking around into early fall. Amid a record-breaking stretch of warm weather in Southern Ontario, it could be a particularly prosperous year for boxelder bugs.

Any idea who this guy is? Found a bunch in southern Ontario
byu/-2008hondacivic- inwhatisthisbug

Homeowners unfamiliar with the mass congregations of insects may be alarmed by the sudden emergence of bug clusters on their property, especially when the bugs find their way inside of homes.

Groups of boxelder bugs have been known to swarm near houses seeking an entry point. Drawn by the warmth of a residence, the insects can cause damage to property when invading in large numbers.

And they're quite good at finding their way into homes, using obvious methods like windows and doors, but also smaller entry points like ceiling lights, outdoor faucets, and even dryer vents.

One way to prevent them from invading your home is to clear any wood, rock, or leaf piles near your home, as well as overgrown plants, and always seal any cracks and crevices that could be used as a means of entry.

Those with inexplicable attachments to piles of debris may end up taking a reactive approach rather than a proactive one.

So what should you do if you've already had your home invaded by boxelder bugs?

The simple answer is to go full Rambo mode and kill them all.

There are a few safe methods to carry out your boxelder killing spree, including vacuuming them up or using a simple mix of soap and water in a spray bottle to chase the invaders out.