Swarms of red and black bugs are taking over Ontario homes right now

It's unfortunately that time of year again when masses of red and black bugs begin swarming homes in southern Ontario in an effort to escape the cold. 

Boxelder bugs (Boisea trivittata), are native to North America and get their name from the boxelder tree, whose seeds are a food source for the nuisance pests. During the fall, the red and black bugs often gather in huge clusters as they leave the trees where they live and feed on during warmer months to find warmer hiding spots in preparation for winter. 

As these insects seek out warmth, you'll notice that the bugs gather in the sunshine on the south side of buildings, trees, and rocks. However, when that heat is no longer sufficient, they'll eventually find ways to enter your home through cracks in the foundation and siding, gaps along windows, and virtually any other small opening. 

Photo: angelaprice/iNaturalist. 

The boxelder bug can be identified by its almond-shaped body, which is black with red edges and approximately two centimetres long. 

With fall now in full swing, many Ontario residents across the province have already uploaded sightings to the social network biodiversity app, iNaturalist. Sightings of clustered boxelder bugs have been reported through the app in Cornwall, Ottawa, London, Windsor, Toronto, Amherstburg, and Kingston, just over the past week. 

While the massive clusters might look frightening, boxelder bugs rarely bite humans or cause any extensive damage to your property with their chewing. You might also want to refrain from squishing them, though, as their guts can exude a stinky stench and can leave permanent red stains on light-coloured materials. 

Photo: milpool/iNaturalist. 

If you're committed to keeping the bugs outside of your home, make sure to repair any holes in damaged window or door screens, install door sweeps, and use good-quality silicone to seal exterior cracks and any cracks or gaps around your windows, doors, siding, and places where utility pipes enter your home. 

Also, be sure to remove leaves, rocks, and boards around your home, as this will discourage bugs from congregating. If you happen to come across bugs in your home, the best means of disposal is to either vacuum them up or gently sweep them outside.