Hey everyone,
I’ve been battling some pretty big roaches in my apartment and decided to try boric acid last week. I spread a thin layer behind the fridge, stove, under the sink—all the usual spots. The thing is… I’m still seeing some huge roaches wandering around at night. Not as many, but enough to make me wonder if the boric acid is actually doing anything.
A few questions I’m hoping to get advice on:
• How long does boric acid usually take to show results?
• Is it normal to keep seeing large roaches for a while?
• Could I have applied it wrong (too much, too little)?
• Should I be using bait or traps along with it?
Really appreciate any insight. I’m trying to avoid calling in a pro unless it’s absolutely necessary.
Totally normal. Boric acid isn’t instant, roaches need to walk through it and groom themselves before it works. For me it took about two weeks before the numbers really dropped.
If you put too much, they’ll avoid it. You’re supposed to dust it super lightly, almost like powdered sugar. A lot of people make that mistake when they first try it.
Yep, big ones can hang around longer because they don’t die as fast as the little nymphs. They don’t groom as often either, so it takes time.
You might want to add some gel bait. Boric acid works great, but bait pulls them out and makes them feed, which speeds things up a lot.
If you haven’t already, check for leaks under your sink. Roaches need water more than food, and if they have constant moisture, they’re gonna hang out no matter what you’re putting down.
It took me 10–14 days before I saw any major improvement. You’ll still see survivors wandering around, especially the big adults. If you’re seeing fewer than before, that’s usually a good sign.
@CityPestDad nailed it, thin dusting only. If your boric acid looks like a snowdrift, the roaches will just walk around it like it’s a wall.
Also, make sure your food scraps and grease around the stove are cleaned up. If they have easy meals, they won’t go near treated areas.
I paired boric acid with sticky traps in corners and that helped me figure out where they were coming from. Might help you track the hot spots.
@BasementBob Bait speeds everything up. Boric acid alone works but it’s slow. If the big ones are still strolling around after a week, that’s pretty normal.