How To Identify And Eliminate Odorous House Ants

This time on PEST PROSpectives, ACE Amber Byars unpacks odorous house ants: how to identify the rotten‑fruit smell, why colonies bud, and where they hide indoors and out. 

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Pest Pros of Michigan

PEST PROSpectives is a Livemic Communications production.

PEST PROSpectives is a Livemic Communications production.

Transcript

Meet Odorous House Ants

Richard Piet 0:08

I'm Richard Piet. Welcome back to Pest Prospectives. This is the podcast from the Pest Pros of Michigan, talking about the creepy crawlies and the things you should know about pest control. Important stuff. Amber Byars is an ACE, and we mean that. She knows her stuff, supervises the field operations at Pest Pros of Michigan, and she is familiar with something called odorous house ants. Hi, Amber.

Amber Byars 0:39

Hey, Richard. Love that name, right?

Richard Piet 0:42

I yeah, so I'm lingering on that because yeah, I think about stink bugs, and I remember saying during our stink bug conversation, you know, I I don't know if my nose doesn't work or what I don't smell stink bugs, but odorous house ants, because the name odorous is there, that sounds worse than stink. It they really do smell.

The Rotten Fruit Smell Explained

Amber Byars 1:08

Yeah, yeah. They they have that name for a reason. So odorous house ants, now it it might sound kind of cruel, but if you if you squish them, they explode with a it's almost like a rotten fruit smell. So it's really good for texts to know um if they're trying to ID uh an ant in the field. That's one of the key characteristics, is if you squish one and smell it. Very similar. I I don't remember um if it was me and you that did this, but we were talking about citronella ants, and we're saying like they literally smell like citronella, same concept except they stink really bad.

Richard Piet 1:42

Yeah, I think we'd like the citronella better.

Amber Byars 1:44

Absolutely.

Richard Piet 1:45

So what do these ants look like compared to, I don't know, carpenter ants and various other ants?

Amber Byars 1:52

Yeah, so they're really small, they're like one sixteenth of an inch to one inch, they're tiny. Um, they move pretty quickly. Um, they have very large colonies, and their colonies can uh do something called bud, they're budding colonies where they'll like separate from themselves, they'll like um break away and create uh little pockets of colonies. So that can be a headache for our clients.

Richard Piet 2:15

Oh my goodness. So when when they're very tiny, we might not even realize what we're looking at.

How To Spot And Where They Trail

Amber Byars 2:23

Yeah, yeah. Well, you know, some folks with bad eyesight might want to want a professional to come look, but you can you can tell pretty clearly that they're an ant and they're usually um in pretty large numbers trailing. And I've I see a lot of them um in the in the kitchen, by the sink, around like very sweet foods or or nectars or syrups, things like that, spillage. So if something spills and you don't know, here come the odorous house ants, and there'll be a lot of them.

Richard Piet 2:52

Okay, so that part is very typical, isn't it? We have, I think, a perception that ants love sweet stuff. It's true for them.

Amber Byars 3:01

It absolutely is, yeah.

Richard Piet 3:03

So if you take away the sweets and you pack things up, put the syrup away, that sort of thing, does that take care of it?

Amber Byars 3:11

No, not necessarily. They will also, you know, seek out harborage areas, um, nesting sites. So if they're around, they will um they'll make themselves known. They'll come out and you'll you'll it'll be pretty clear. It's not necessarily just a source issue.

Richard Piet 3:26

Okay. And they're small, but they still stink.

Amber Byars 3:31

Yeah, yes, absolutely. Yeah, they do. It's it's the weirdest thing. Like um, something that we find pretty cool because we're bug nerds, but um not not great for a client, you know. They're cleaning up a mess or they're you know wiping down the counter, trying to clean up the ants that way. There can be that kind of pungent smell.

Richard Piet 3:49

Okay. Wow. So I'm wondering that that seems unusual to me. Uh and folks who are smelling this, maybe they're smelling it, but not necessarily seeing the bug right away. What's that smell? And they they might not realize what we're dealing with.

Amber Byars 4:08

Maybe I've never seen that or heard of that, but that's a possibility.

Richard Piet 4:12

Okay. So they're not that small, not that small.

Amber Byars 4:15

I mean, definitely um clear to the naked eye for sure. And back to like the sweets and the the syrupy um materials, they will definitely switch over to other food sources as well, proteins and things like that.

Richard Piet 4:29

Okay. Uh, and as you said, they branch off and have sort of sub-colonies. This could be tricky.

Budding Colonies And Why It’s Hard

Amber Byars 4:38

Yeah, so it it's a process called budding. So they'll they'll break away. Um, carpenter ants are very similar. Well, they'll have satellite colonies around, but um, the budding process is very interesting with the with the odorous house ants. And again, if it's a structural issue, um, that can make control very challenging.

Richard Piet 4:57

Yeah. So the odorous ants, I mean, we know carpenter ants kind of like wood and and that sort of thing. What about these guys with the with the sweet stuff? They're attracted to that and proteins, but when they make their colony or their when they bud and they go away, what makes them comfortable otherwise? Do they want to be near that stuff or do they go travel to it?

Amber Byars 5:20

You know, they're really diverse. You can find them a lot of plACEs. They will nest pretty much anywhere inside. You're looking at, like in the wall voids, beneath flooring, insulation by pipes, like leaky pipe fixtures. Um, outside, you're looking at you they could be underneath firewood that's stacked up. They could be exposed. I found these these big nests in garage framing, like the exposed framing, um, where they're kind of all right out in the open, and then the trail starts from there.

Richard Piet 5:53

Oh boy. Okay. So they could find a comfortable spot in a lot of plACEs. So they could be anywhere.

Amber Byars 6:01

Anywhere. Yeah. Yeah. They're very diverse. They can acclimate pretty well.

Richard Piet 6:06

So, how do you attack it? When you uh discover odorous house ants are the problem, how do you approach it?

Nests Indoors And Outdoors

Amber Byars 6:13

So, with most of the time on the inside, it's very rare that we can actually find the colony or the nest. So we do our thorough integrated pest management inspection, of course. We try to see if there's anything conducive on the property that is attractive to them that we can educate the client on. Uh, there's some spillage here, or hey, the door is left wide open, or whatever the case is, or there's really a lot of access points here. They're so small that that could be pretty much the whole home. But as far as interior treatment, we would start there with attacking what the where the activity is. And we utilize gel bait most of the time for initial services where we will test out a few different baits that we have because during certain times of the year, again, we know that they're really a sugary ant. So we try high sugar baits first, but sometimes they're not attracted to that. And though we'll try other baits. So baiting is the first option for sure. It's very, it's non-invasive. Um, you can do it very discreetly. And if they're feeding on the bait, then we can put enough bait down where they can take that back into the colony.

Richard Piet 7:26

That was going to be my next question. So the bait then travels back with them.

Amber Byars 7:31

Yeah. Yeah. So a lot of the baits on the market right now have that transfer effect to them, the non-repellent transfer horizontal effect effect, however you want to call it, where if they consume that bait and then they groom each other and they share food between each other, that's all being passed along.

Richard Piet 7:51

Okay. Yeah. Uh, so that is the most common way that you would attack it then. You can't find the colony. So you've got to have them either come to you or it's got to go back somehow.

IPM Basics And Client Education

Amber Byars 8:03

Yeah. And so um, how we train our guys is, you know, if there's an adequate amount of activity that they're going that we can bait, do that. Uh apply uh a gel bait in an in enough amount where it will control them. If there's not, because sometimes we get on the property and it's so weird. This happens so often that when the pest control people come, everything's gone. Like they're nowhere in sight. They they've went they've gone away um by the time we got there. So later on that night they'll be back. So sometimes it's more appropriate at that point, if we're not physically seeing them, to really pick our clients' brains on where the trail was, where they're seeing them, then apply a non-repellent liquid product. Um, liquid products can stay, they're residual, they can last a really long time. And so we'll leave that product in really heavily populated areas where the client was noticing them, and we'll do spot treatments there. So that way when they come back, that product will be there. The hard problem with baiting for ants that aren't physically present is we don't know what they're going to be attracted to or receptive of. So we will lean into the the non-repellent liquid instead, which works really, really well.

Richard Piet 9:12

So they're smart because they they come out at opportune times and they seem to know when to retreat. And this makes it more complicated, doesn't it?

Amber Byars 9:22

Yeah. And sometimes, you know, it could just be that they've came out and they've gotten the resources that they need and they're taking it back into the colony, and it just happens to be a coincidence at that point. But um, but yeah, it's just funnily, like sometimes when we get on the property, everything has dispersed. And so we have to have multiple tactics to be able to control them at that point. Um, exterior treatments are great because again, odorous house hands will come up from the inside, from the outside in. And so we are we're gonna be looking for transitional points where they could have accessed the home. So barrier treatments are great. Again, non-repellent products, so we can get that good horizontal transfer between the insects that way. But exterior treatments are absolutely a big part of an odorous house hand treatment, especially if we notice that the colony is primarily outdoors.

Richard Piet 10:12

So is that a winter-summer difference? You might do a perimeter kind of outside treatment in the summer, or does it not matter?

Amber Byars 10:23

Yeah, so um the in the winter, it's much less likely that we'll be doing exterior treatments with liquid, unless we have a day like today in Michigan where it's almost 60 degrees. So um we could definitely utilize some exterior liquid applications today, but most of the time we're gonna be doing crack and crevice treatments. We could utilize dust, we could utilize that gel bait, especially if we're seeing them actually enter the structure.

Richard Piet 10:49

All right. So seasonal situations um apply in these cases. So that's uh something to expect. What else should a homeowner expect when all of a sudden uh they have these ants, you've come to treat them, and they're gone, right? It's over.

Baiting Strategy And Transfer Effect

Amber Byars 11:10

Yeah, I wish that would make that would make our jobs and our clients so much happier and easier. But no, um, we're really good at explaining and setting that expectation up front, um, especially with an ant colony, and as as populated as an odorous ant colony can get, that that takes some time. So the non-repellent products, they are designed to be very, very slow acting intentionally to get to the queens of the colony. Um, one thing that we uh train against with ants, especially a colony of ants, if we're attacking an active issue, is to stay away from the repellent products, the repellency-based insecticides, because that will do a lot of good up front for the worker ants, the ones that they're seeing physically. It will kill them pretty quickly. But the long-term success rate is very low because it doesn't make it back into the colony wherever the colony is. Again, some most of the time we're treating for these ants, we're not sure where the colony is located. Sometimes, by happenstance, we can find it by a thorough inspection, and that takes a lot of time. Um, or sometimes you'll just get lucky and you'll find one right out in the open. But if not, we really want to make sure that we're using the right products. Um, a lot of the times homeowners will go buy over-the-counter products like RAID and they'll treat themselves absolutely, but then they'll get that frustration afterwards because it didn't take care of not getting to the source at that point. I I know, and we've done a a DIY um podcast before, and so that all is very relevant.

Richard Piet 12:46

Yeah, check it out. If you haven't subscribed, by the way, to Pest Perspectives, do that, and then you'll hear when these episodes come available, and you can pick and choose the ones that might apply to your situation. Is there any kind of structural concern with odorous house ants? Are they that destructive?

Amber Byars 13:03

Um, not no, they're just no real structural concern. Um, they're not a like health threat or anything. They are a huge nuisance. There's also like outside, I don't think we touched on this earlier, but harborage areas outside can cause some issues for the structure as far as trees touching. Odorous halcians will tend to aphids. They'll use them for that sugary material that they excrete, the aphids with the honeydew. And so what we see a lot is that can also transfer into a home if that tree or bush or whatever that they're tending these aphids on is contacting the structure, then that can cause an entryway in or at least give them a leg up on that. So we will always recommend, as far as structurally goes, to trim back vegetation, make sure things are nice and tight and sealed up. But again, um, exclusion with ants is is almost impossible because they're just so small and opportunistic that they will find um a way in unless you sealed up every single millimeter of a home, which just doesn't happen. But no structural damage related though.

When Ants Vanish: Liquids And Residuals

Richard Piet 14:10

Okay. Well, that's uh helpful to know. But nevertheless, if you're looking around on the outside of the house, you're gonna see some of these things. We've talked about the the vegetation and things that could be a pathway. You're gonna be looking for that.

Amber Byars 14:24

Yeah, absolutely. Mulch right up against the structure, the vegetation, trees touching, moisture issues, leaks, anything like that.

Richard Piet 14:33

Okay. You see ants, you smell ants in this case. You'll want to reach out and talk with Amber and the team at Pest Pros and ask about it. It could be odorous house ants. P U. We don't want that. All right. Details in the show notes. Click through, find more of our episodes, and lots of information on the Pest Pros website as well. Amber Byars, Pest Pros, thank you.

Amber Byars 15:00

Of course, thank you.