Still finding big roaches a week after using boric acid — normal or failure?

Insects & Creepy-Crawlies
1

Hey everyone,
I treated my apartment with boric acid about a week ago after spotting roaches mainly in the kitchen and bathroom. I followed the usual advice — light dusting along baseboards, under appliances, and behind cabinets.

Here’s what’s worrying me: I’m still seeing fairly large roaches, not dead ones, actually moving around at night. I expected to maybe see a few dying bugs, but live adults a week later feels discouraging.

So I’m trying to figure out:

  • Is this still within the “normal” timeline for boric acid?
  • Or does this mean it’s not working for my situation?
  • At what point should I switch strategies or call a pro?

Would really appreciate hearing others’ experiences.

2

Totally normal, honestly. Boric acid is slow-acting. The big ones you’re seeing now may not have contacted it yet, or they’re coming out because the colony’s being disturbed. It’s not an instant-kill product.

3

I went through the same thing last year. Week one looked like “nothing is working,” week two was actually worse, then suddenly the numbers dropped off hard. Stick with it a bit longer.

4

One thing people miss is placement. If the boric acid is too thick or too visible, roaches will avoid it. Light dusting is key — barely visible, not piles.

5

Are you sure they’re German roaches? If they’re big and slow, could be American or smokybrowns coming in from outside. Boric acid won’t stop new ones from wandering in.

6

@HomeFixerJay How clean is the kitchen at night? I noticed boric acid worked way better once I removed all food sources overnight. Otherwise they just ignore the poison and go for crumbs.

7

I’ll be honest, boric acid alone didn’t finish the job for me. It helped, but I had to add gel bait for real results. The combo is what finally wiped them out.

8

Seeing live roaches doesn’t mean failure yet. What would worry me is seeing babies after 2–3 weeks. Adults can linger, but new nymphs mean reproduction is still happening.

9

Seconding what @RoachFacts said. I redid my application lighter and more targeted and that made a huge difference. Thick lines of powder just don’t work.

10

If you’re in an apartment, also consider neighbors. Boric acid won’t help much if the unit next door is infested and untreated. Roaches don’t respect walls.

11

One week is too soon to call it a failure. Give it at least 3–4 weeks, monitor activity, and be ready to pivot if numbers don’t drop. Boric acid is patience-based warfare :sweat_smile: