Will Bleach Kill Drain Flies? Discover What Actually Works

Drain flies are annoying, especially when they keep coming back. If you’ve spotted them near your sink or shower, you’re probably wondering if bleach can wipe them out.

This quick guide breaks down whether bleach really works—and what else you can do to stop these pests for good.

Will bleach kill drain flies?

Yes, bleach can kill drain flies on contact, but it won’t eliminate the deep gunk where they breed, so it’s not a complete fix.

Key Takeaways:

• Bleach can kill some drain flies and larvae but won’t remove their breeding ground.
• It’s best used with a deep clean—hot water, scrubbing, or enzyme cleaners.
• Regular upkeep helps prevent reinfestation.
• If flies persist, professional help may be needed.

What Are Drain Flies?

Drain flies, also known as sink or moth flies, are tiny bugs with fuzzy wings and a love for moisture.

You’ll usually spot them chilling around sinks, tubs, or floor drains. They breed in that slimy gunk inside your pipes—the kind you’d rather not think about.

They don’t bite, but they multiply fast and get annoying real quick. If you’re seeing more than a couple, it’s a sign your drain’s got buildup that needs attention.

Get ahead of the swarm by scrubbing out that slime or treating it before they settle in like it’s a timeshare.

Can Bleach Kill Drain Flies?

Bleach can kill drain flies, but it’s not the silver bullet most people think it is.

It’ll wipe out some larvae and maybe a few adults, but it doesn’t always reach the root of the problem—deep organic gunk in your pipes.

If you’re using bleach, go in strong. Pour it down the drain at night when pipes are quiet.

Just know this: it’s more of a short-term flex than a full-on solution.

Want real results? Pair bleach with a proper drain scrub and stay consistent. One hit won’t cut it.

How to Use Bleach to Kill Drain Flies

Start by pouring hot water down the drain to loosen up any grime. This warms the pipes and preps the scene.

Next, grab regular household bleach—nothing fancy—and pour about a cup slowly into the drain. Let it sit overnight. This gives the bleach time to break down gunk and larvae.

The next morning, flush it all out with hot water again. Repeat for a few nights if flies keep showing up.

Bleach can handle surface-level issues, but if they’re still partying in your pipes, it might be time to dig deeper or call in backup.

Does Bleach Remove the Source of the Infestation?

Not really. Bleach can kill some adult drain flies and larvae on contact, but it doesn’t fix the root problem.

The real issue is the gunk inside your drain—built-up grime, hair, and organic slime. That’s their party spot.

If you don’t scrub that slime layer out, they’ll keep coming back like it’s happy hour. Bleach might give the illusion of a quick win, but it’s surface-level at best.

You need a solid deep clean—think boiling water, a stiff brush, maybe even a drain gel that clings and cleans.

In short, bleach is a band-aid, not a fix. Want ‘em gone for good? Kill the vibe and their hangout.

Alternatives to Bleach for Drain Flies

1. Baking Soda + Vinegar Combo

Old-school but solid. Pour half a cup of baking soda, then a cup of vinegar down the drain. Let it fizz and chill overnight. Rinse with hot water in the morning. Works like a charm.

2. Boiling Water Flush

No frills, just boiling water. Hit your drains with it daily for a few days. It helps clear gunk that flies love to party in.

3. Drain Gel Cleaners

Grab a bio-enzyme drain cleaner from the store. These break down organic matter without the drama of bleach. No harsh fumes, no fuss.

4. Pipe Brush + Soap

Scrub it old-school. A flexible pipe brush plus dish soap can clear out that grime sitting in the trap, AKA fly central.

How to Prevent Drain Flies Long-Term

1. Keep drains squeaky clean

Flies love that slimy gunk sitting in your pipes. Hit your drains weekly with hot water, baking soda, and vinegar to keep things flowing and less fly-friendly.

2. Dry it out

Drain flies thrive in damp zones. Wipe down sinks and showers after use. If water’s pooling, it’s basically party time for pests.

3. Cover your bases

Got a drain you barely use? Cap it or flush it regularly. Standing water’s their VIP section—shut it down.

4. Fix leaks fast

Even a slow drip under the sink can become a five-star fly hotel. Tighten things up before it turns into a full-blown infestation.

Stay one step ahead, and you won’t need bleach to play cleanup crew later.

When to Call a Professional

If bleach didn’t budge the bugs, it’s time to tag in the pros. Drain flies can hang out deep in pipes, past where your cleaner can reach.
Still spotting them after a few days? That’s your cue.

A licensed pest control tech has tools that go way beyond your local hardware store.
They’ll clear out the source and make sure you’re not dealing with a bigger issue like a broken pipe or hidden leak.

No shame in asking for backup—especially when bleach just doesn’t cut it.

Frequently Asked Questions

1. Does bleach actually kill drain flies?

Yeah, it can—but only on contact. Bleach won’t wipe out the whole colony living in the gunk inside your pipes.

2. How often should I use bleach to treat drain flies?

Using it once might help a bit, but it’s not a long-term fix. Clean the drain regularly and treat the source, not just the symptoms.

3. Is bleach safe for all drains?

Not really. It can damage older pipes or septic systems. If you’re unsure, try enzyme cleaners instead—they’re way gentler.

Conclusion

Bleach can kill drain flies, but it’s more of a quick fix than a full-on solution. It might wipe out a few, but it won’t touch the eggs or the gunk they live in.

For real results, clean your drain properly and follow up with consistent upkeep. A scrub brush and enzyme cleaner? Way more effective long-term.

So yeah, bleach might feel like the fast track, but don’t let it be your only move. Treat the cause, not just the swarm, and those flies won’t stand a chance.