Store-bought roach spray often creates the illusion that the infestation is getting better because a few visible roaches die quickly. The real problem is that the visible roaches are only a small part of the colony. Most of the infestation stays hidden behind appliances, inside cabinet gaps, under sinks, and inside walls.
Roaches do not live out in the open
German cockroaches especially prefer tight harbourage close to food and moisture. They gather in protected spaces where casual spraying does not reach them well. Egg casings and younger stages stay protected there too.
Spray can push the infestation deeper
One of the biggest problems with over-the-counter spray is that it can scatter roaches away from their original harbourage. Instead of eliminating the source, it may push them deeper into cracks, voids, and adjoining spaces where they become harder to control.
Why the problem comes back fast
If the nest remains active, new nymphs emerge and the sightings start again. People then spray again, creating a cycle of temporary relief without true elimination.
What works better
Professional treatment targets the harbourage using the right products in the right places. That usually means baiting, void treatment, and a layout-specific approach rather than broad visible-area spraying.
If your roach problem keeps returning after spray cans and DIY products, the colony is likely still active behind the scenes. AstraHive Pest Control provides licensed cockroach treatment with a thorough multi-step approach. Call 905-925-8427 for a free consultation. Same-day service available across the GTA.