You’ve just invested in professional pest control. You expect instant silence and empty traps. So it’s understandably alarming when, hours later, you see more ants marching across your kitchen, a spider scurrying from a baseboard, or a roach looking disoriented in the middle of your floor.
Your first thought: Did the treatment make it worse? Did I just waste my money?
Take a deep breath. What you’re experiencing is often normal. It’s called the Bug Surge or Flush Out Effect, and in many cases, it’s a sign that the treatment is actually working.
Here’s a breakdown of what’s happening inside your walls and when you should and shouldn’t be concerned.
The 3 Reasons You See More Pests After Treatment
1. The Last Stand of the Colony This is Good
When a non-repellent insecticide is applied, pests cannot detect it. Ants, roaches, and other insects walk through the treatment and carry the active ingredient back to their nest. As the poison begins to disrupt their nervous systems, they become disoriented and hyperactive.
What you’re seeing: Erratic, slow moving pests out in the open during the day. This is their final, desperate activity before the colony collapses. They are emerging from their hiding places because they’re dying.
2. The Scatter Effect from Repellents This is Manageable
Some treatments, particularly older formulas or DIY sprays, are repellent. Pests sense them and flee their harborages to avoid them. This can temporarily scatter the population to new areas of your home.
What you’re seeing: Pests in rooms where you’ve never seen them before. This is why professionals prefer non-repellent strategies they kill the colony instead of just moving it around.
3. The Population Was Already There This is Revealing
The treatment didn’t create more bugs; it revealed the true scale of the infestation you were already living with. The pests you see now were always hidden deep in your walls, under your floors, or in voids. The treatment has forced them out into the open.
The Critical Timeline: What to Expect After Treatment
Hours 1-12: You may see a significant increase in activity. Don’t spray them! You could interrupt the transfer of poison back to the nest.
Days 1-3: Activity should begin to sharply decline. You’ll see mostly dead or dying insects.
Days 4-7: You should see very little to no live activity. A few stragglers might appear.
Week 2+: Your home should be pest free. If activity persists or increases, it’s time to call your exterminator back.
Red Flags: When More Bugs Signal a Problem
While a temporary surge is normal, certain signs indicate the treatment isn’t working as planned. Contact your exterminator immediately if you see:
- Live, healthy, fast-moving pests 4-5 days after treatment.
- An increasing number of pests each day after the first 48 hours.
- New pest evidence e.g., frass, droppings, nests a week after service.
- No change whatsoever in pest activity after 3 days.
My Treatment Failed A Seattle Case Study
“We had AMPM treat our Ballard home for carpenter ants. The next day, I saw 20+ large ants in my living room. I was furious and called them, convinced it failed. The technician calmly explained it was the flush out effect. He was right. By day three, the activity completely stopped. A week later, it was like a switch had flipped. The problem was just bigger than we realized.”
Michael R., Ballard Homeowner
Your Action Plan: What to Do and Not Do After Treatment
DO:
- Be patient for the first 48-72 hours.
- Keep the treated areas dry.
- Vacuum up dead pests to clean up.
- Trust the process and communicate with your exterminator.
DO NOT:
- Use store bought sprays or bug bombs. This will ruin the professional treatment.
- Clean the applied areas like baseboards and cracks for at least a week.
- Panic! The process takes time to work through the entire population.
Still Seeing Too Many Pests? We’re Here to Help.
If you’re past the critical 72 hour window and the bug surge hasn’t subsided, your treatment may need adjusting. Sometimes, a hidden satellite nest or an unexpected entry point requires a follow up strategy.
Contact AMPM Exterminators for a free follow up assessment. We’ll determine if what you’re seeing is a normal flush-out or if your home needs a different approach.
Call (206) 571-7580 to speak directly with a technician about your post-treatment concerns.
Questions? Share Your Experience Below
Have you experienced the bug surge after a treatment?
- How long did it last?
- What type of pests did you see?
- Did it eventually work?
Our technicians monitor these comments daily and will respond to your specific situation. Your experience can help other Seattle and Eastside homeowners know what to expect.