Identification, Biology and Behaviour of Structural Pests
Identify first; the treatment depends on it
You identify structural pests by body shape, antennae, waist, wings, legs, size, mouthparts, droppings, damage and signs. Learn the discriminators for the groups Ontario exams love.
Cockroaches: German - 13–16 mm, two dark stripes on the pronotum, prefers warm, wet harbourage near kitchens and dishwashers; American - larger, reddish brown, sewer and basement associated; Oriental - dark, cooler and damper.
Ants versus termites: ants have elbowed antennae, a pinched waist and unequal wings; termites have straight bead-like antennae, a broad waist and four equal wings. Ontario's structural termite is the eastern subterranean termite, which builds mud tubes.
Ants: carpenter ants are large, one node, and push out sawdust-like frass from galleries in wood; pharaoh ants are tiny and yellow with multiple queens and will "bud" into new colonies if sprayed with repellents.
Rodents: house mouse droppings are roughly 3–6 mm, pointed; Norway rat droppings about 18 mm, blunt, with burrows at ground level; roof rats climb.
Also know stored-product pests (Indian meal moth, saw-toothed grain beetle), small flies (fruit, drain, phorid), bed bugs (flat, oval, 4–5 mm, hiding in seams), carpet beetles, clothes moths, silverfish, cluster flies, wasps and spiders.
Traps: confusing ant and termite features; mistaking a cockroach nymph for another species; mixing up mouse and rat sign; confusing bed bugs with bat bugs or carpet beetles; treating on one sighting without confirming an infestation.
Rule of thumb: if you cannot name the pest, do not treat - behaviour (harbourage, moisture need, feeding) determines the placement and the product.