Okay, you’ve stuck with me for three other posts about the composting toilet and we’ve made it to the last two. Yes, I know when I started the series, I said there were four. (And yes, I know I said I’d stop predicting how many posts would be in a series because I’m always wrong. But this time, I was so sure i’d be right.) Unfortunately, these last posts are also the ickiest. But I wouldn’t be doing a proper job if I didn’t address the nasty issue of a bug infestation in your composting toilet. Today, I want to offer a few theories about bugs then move on to ideas for preventing bugs in the composting toilet to begin with.

I’ve been writing notes about the composting toilet for more than a year now in preparation for writing these posts. One note which I took from somewhere but couldn’t find where said: A well-functioning, well-maintained compost toilet will not get bugs. This was before I got an infestation myself and before I realized that statement is absolutely not true. A well-functional, well-maintained compost toilet absolutely can get bugs.

Do Black Tanks Get Bugs?

So, when I’m at full hookups, I connect the sewer hose, open the gray tank and leave it open. This means the entire time I have zero water accumulating in my gray tank because it’s continually draining into the sewer.

But, apparently, when you have a black tank, it’s a best practice to keep the black tank closed. Then every few days, you open the tank so it can empty down the sewer. The reason? Sewer flies. They come up from the sewer looking for a place to lay eggs and if the sewer line is open, they can eventually reach the toilet and get inside of the rig.

My theory is that those are the same bugs that can find their way into the composting toilet. But what’s interesting is that I’ve never heard the term sewer flies used to describe the bugs that get into the composting toilet. They aren’t even called flies. Everyone just refers to them as bugs.

But they are black and they do fly. However, they are tiny, from poppy seed size to sesame seed size. So much smaller than any fly I’ve ever killed in my house. So, are they the same creature? The answer is really neither here nor there when it comes to this post but I find it interesting so if you know the answer, I’d love for you to share it in the comments.

More Theories

If bugs and sewer flies are the same—and, I suppose, even if they aren’t—this leads to the natural next question. If you don’t have a black tank which means the bugs aren’t coming up from the sewer, how do bugs get into the composting toilet? It’s a head scratcher.

There are two ways that I know that they found their way into mine. First, as I said, those suckers are tiny. So tiny, in fact, I actually saw them find their way into my rig by coming in through the mesh screen in my windows. Just walked right in like they were invited. I should say here that them getting into your rig doesn’t automatically equate to them getting into the compost. Once inside your rig, I think they fly in through the hole in the side of the toilet used to pull in air (not the side attached to the vent tube).

Second, the vent tube on the compost toilet is clear and I have seen lots of bugs in that tube. I think what happens is that they can smell the human waste coming from the exit point of the venting before it’s had the chance to break down in the compost. They are attracted to it and follow their little buggy noses down until they reach pay dirt, so to speak. Or, should I say poop dirt?  

I suppose we also shouldn’t dismiss the simple entry point of the door. You open the door on a regular basis and, even if you shut it right away, it’s still plenty of time for pests to find their way in.

On the Oliver Owner Facebook group, we’ve had many discussions on this topic. Recently, someone theorized that it seemed possible for eggs to be in the coconut coir and once hydrated and used, it makes for an ideal time for them to hatch. The theory is if you have secured all the other entry points, what else could it be? If it’s true, it kind of sucks because it also means getting them at some point is inevitable.

Tips for Preventing Bugs

Based on what I said above, most of this will be obvious. But here is the quick list of things you can do that should help in preventing bugs from getting in to start an infestation.

• Keep bathroom window closed (particularly in humid locales).
• Keep compost toilet lid down.
• Place a single layer of a woman’s nylon over the vent tube and over the hole on the opposite side of the toilet (do so with a little slack on the vent tube as you’ll have to then slide it back onto the toilet).
• Cover over the place where the vent leaves the rig. I’m not exactly sure the nitty gritty of this one but, basically, I’m saying try to prevent them from getting into your vent tube to begin with. I admit I haven’t crawled to the top of my rig to do this one yet. I’m wholly relying on them to be blocked by the nylons.
• Keep a close eye out for those nasty flying creatures. Be vigilant.
• This next prevention idea is not one I have tried but one that I read about. Get a mothball cake and attach it to the underside of the top piece of the composting toilet. They are stinky but the fan should vent any smell. I guess how it works is the bugs don’t like the smell so they stay away. If anyone has tried this method, I’d be curious to know about your results.
• If you start to see telltale signs, act immediately. Those suckers produce faster than proverbial rabbits. And a small problem can become a big problem in a very short time. I know of what I advise. My own infestation was made so much worse by the fact I just kept ignoring the flying little creepers around inside my rig. I mean, I was killing them with my fingers (because they are so small it doesn’t seem that gross to me when I squish them flat) but not asking myself why I had them or why they were moving in.
• Don’t leave dirty dishes in the sink.
• Store food away. I put my bananas and other fruit in a bowl in my microwave. This may or may not have anything to do with helping to keep bugs out of your composting toilet, but let’s cast a wide net here. They might come in for the sugar from a banana and stay for the poop. Trust me when I say, for being such itty-bitty brained creatures, they are awful clever.

• As stated, they are attracted to sugar, so if you end up with some flying around inside your rig, put some apple cider vinegar in a jar or a glass with a couple drops of dish soap. You’ll get a bunch of black floaties in no time. Another liquid with sugar content is wine. So, a glass of that will also do the trick.  If you have a glass of it out for consuming, cover it with a paper towel or little plate or you might end up with some added protein in your adult beverage.
• Not sugar related, but you can also try sticky fly rolls. However, before you rush out and purchase this highly-effective tool for trapping and killing bugs, read the next section.
• Make sure the fan stays plugged in. Again, not sure this has one iota to do with bugs but let’s cover all the bases. (In the photo in the above section, the round thing on the top right corner of the square is where the fan power source is.)
• Keep compost at the ideal level of moistness as described in previous posts. Do not let it get too wet.
• And, finally, if you get an infestation, don’t panic. I know it’s icky and not fun, but you’ll get to the other side. I say this because, I’ll be honest, when I got the infestation especially as it kept getting worse (more on that in a minute), I had serious doubt about all of RV life. Not just the composting toilet, but RV life itself. I felt defeated and a little bit like it might be time to cut my losses.

And Yet Another Cautionary Tale

Okay, I know I may not come off as the sharpest tool in the shed sometimes because I confess so many “lessons I learned the hard way.” But even so, this one was so funny and stupid, so I just had to share.

In the midst of my infestation which you’ll read about next week, while I was waiting for any number of the solutions to start working, I had those nasty little flies flying around my rig. Gross. Since I could see them in the air, I decided to purchase some fly strips. You know those? They are the super sticky yellow-gunky things that hang down and when a fly (or anything really, as you’ll see) gets stuck on it, they are stuck for good.

While I was okay with spraying killer bug spray in the composting toilet, I definitely was not okay with spraying it in my rig where I and my pets might breath it in. The fly rolls or ribbons (as I learned they are now called) seemed like the perfect solution, killing bugs in the air without killing me or the pets.

Because of the bugs and since I was regularly spraying the inside of the toilet, I also started keeping the bathroom door shut which is not something I normally do. The bugs were predominantly in the bathroom so that’s where I hung my nifty bug-killing super-duper sticky fly strip, right over the toilet where the bugs who hadn’t found their way in seemed to hang out the most.

Can you see where this is going?

Yep, it’s the middle of the night and I head to the bathroom in the dark. Screams come from the bathroom because who needs to turn on a light in such a tiny trailer? Yep, my head hit the fly strip full-on. I picked glue out of my hair for a while after that.

And the very worst most embarrassing part of this story? A few days later, I did it again.

Needless to say, I cannot personally recommend using fly rolls.

Next week, I’ll will tell the story of my bug infestation as well the lengthy process of hit-and-miss solutions I tried before finally getting rid of the gang who’d taken over my rig once and for all. If you have other ideas for prevention, please share them in the comments.

Previous Posts about Composting Toilet:

• Composting Toilet: What Is It and How Does It Work?
• Preparing and Emptying the Compost Toilet
• Composting Toilet: Maintenance and FAQs

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