An unfamiliar bug in the house, and the same question comes up: is this serious? In Quebec, the vast majority of small creatures found indoors are harmless and simply point to moisture or a gap. A few, however, call for quick action. This guide sorts them by where you see them, with a link to the article that tells you what to do.
Three questions to identify a bug
- Where is it? Kitchen, bathroom, basement, bedroom, windows: each place has its usual suspects.
- When? Several insects only come in at a specific time of year. A bug at the window in October is not the same one as in July.
- How many, and for how long? A single bug is not an infestation. Several a day, for weeks, is.
Take a sharp photo with a coin for scale: that is often enough for a technician to tell.
In the kitchen
- Small ants in a trail to sugar or crumbs: pavement ants or Pharaoh ants. See how to get rid of ants and our Pharaoh ant profile.
- Large black ants, especially in the evening, sometimes with sawdust: carpenter ants. Don’t let it go.
- Tiny red-eyed flies around fruit and the sink: fruit flies.
- Grey and copper moths flying in the evening, silk in the cereal: pantry moths.
- Flat brown insect that runs from the light under appliances: possibly a cockroach. See our cockroach profile. Act quickly.
- Small black droppings like grains of rice in drawers: not an insect, those are mouse droppings.
In the bathroom and basement
- Small, fast silver bug with three tail bristles: silverfish. A sign of moisture.
- Creature with very long legs racing across the wall: house centipede. It eats other bugs.
- Small grey armoured bugs, sometimes rolled into a ball: sowbugs and pillbugs. Moisture near the foundation.
- Brown bug with pincers: earwig, mostly in summer.
- Spiders in corners and webs: see how to keep spiders out.
In the bedroom
- Small reddish-brown, flat, wingless bug, and bites when you wake up: possibly bed bugs. Compare with our article on bed bug bites and our bed bug profile. Act fast.
- Brown, hairy larvae under the bed or along rugs, holes in woollens: clothes moths and carpet beetles.
- Tiny black jumping bugs, bites on the ankles, a pet in the house: fleas.
At the windows, from September to spring
Three insects spend the winter in walls and attics, then reappear at the windows on mild days:
- Small orange beetles by the dozen: Asian lady beetles.
- Large brown bug, shield-shaped or long: fall stink bugs (brown marmorated, western conifer seed bug). They are not bed bugs.
- Slow, clumsy flies at the upstairs windows: cluster flies.
For all three, the fix is the same: seal the openings at the end of summer.
A small black bug in the house?
It is the most common search, and the answer depends on size:
- 6 to 13 mm, an ant: carpenter ant, especially in spring.
- 3 to 5 mm, oval and smooth: black carpet beetle, a carpet beetle, often near windows.
- 1 to 3 mm, jumps: flea.
- Small black fly near plants or the drain: fungus gnat or drain fly, both tied to moisture.
When to call a professional
- You suspect bed bugs, cockroaches or carpenter ants: those three don’t go away on their own.
- You see the same bug every day for more than two weeks.
- The bugs show up in several rooms.
- You don’t know what it is.
An inspection identifies the insect, finds where it comes from and deals with the cause. Our certified technicians work with entomologists, and the estimate is free. For year-round prevention, see our home protection plan. Contact us or call 514-638-8705, 24 hours a day.