Sugar ants aren’t pests – they’re harmless and helpful!

This very popular blog post has been refreshed and updated for Spring 2024 (and thereafter).

Photo caption: A legion _{(not an army, but part thereof!)} of sugar ants committed mass suicide in my bottle of honey. In honour of those that might resurrect – I can see some of them will – I pooled it in the sink and gave them a chance to extract themselves (and several did). A few less foolhardy brothers and sisters are supping from the edges.

It’s spring again— and people don’t know what to make of the teeny-tiny ants that march indoors like school children on spring and summer days (when they should be outside!). They can’t be mistaken for carpenter ants. But, unfortunately for them and all the other ant species that aren’t carpenter ants, all searches end up on results about killing them. As if they were as dangerous as carpenter ants. Carpenter ants won’t hurt you, but their infestations are dangerous to your house – they devour wood.  They’re the only ones you need to be vigilant about. (OK, maybe fire ants too, but usually they’re outdoors, minding their own business).

Common talk, mass media, and the extermination industry has effectively enabled people to think that insects are disgusting and undesirable. This is just flat-out wrong. Bugs aren’t your enemy. All it takes to realize that, is to observe them objectively, doing nothing but watch—and if that isn’t enough, it always helps to do a little research.

Of course, when you try to do some research, you have to get past the “get rid of” them websites. The truth takes lot more digging. So that’s what this blog post is about.

So, those teeny-tiny ants you see in spring, visiting your plants, maybe visiting the fruit on your kitchen counter? The name of this kind of ant is Tapinoma sessile. Here’s the path I took to research it some more:

1. WikiHow’s excellent self-education article “How to Identify Ants.” I learned a lot about ant anatomy here! For example, their third section, the abdomen, is called the gaster. You should note what colour it is when identifying the type of ant.
2. From there, I discovered Ant Web, which is like an atlas of species. It’s obviously meant for researchers, but it’s quite the remarkable resource. Did you know the ant family is called Formidaceae? Because they are formidable! (That means wonderful, in French. And impressive, force-wise, in English.)
3. From there, I found the Discover Life website, but I quickly became overwhelmed and bounced. It’s a place to bounce back to whenever one wants to research any plant or animal.
4. At many of the many “get rid of them” extermination websites, they will at least tell you some facts about the species. (They’ve got better jobs to do than eliminating “pests” that are temporary, seasonal, and not really pests at all.) This page helps you determine which common ant you might have.
5. And finally, AntWiki! When you start with the species name, it’s easy to get to the real resources on all things about ants — or any other form of life.
6. As a bonus, there’s Texas A&M’s AgriLife Extension website, Insects in the City. The focus may be on Texas, but it has a lot of info, and they’re definitely on board the biophilia train. The next quote comes from them:

[Tapinoma sessile] are attracted to sweets. Odorous house ants most commonly nest outdoors, but will also nest in bricks and wall voids and other interior locations.

Identifying household ants, accessed May 27, 2019

When sugar ants first made their appearance in my kitchen in June of 2010, I’d never really noticed them before, but suddenly it seemed everyone was noticing them. Killing them was never my thought. Yes, there were many of them, but I was curious: why are they here?

Relevant: I left the maple syrup out on the counter, and they were attracted by the sugar in the ring mark from the bottle. Once they ate all the sugar, they marched off to look for something else sugary.

Indeed it seems that sugar has been an evolutionary key to colony immunity from infectious disease. As ants are eusocial – always in cooperative groups – this would be a serious benefit.

NPR did a special on sugar ants in “The Tiny Ant that’s Taking Over the Big City.” (The comments for the article are illuminating.)  Sugar ants are able to create supercolonies that they could not sustain if they were in the forest. However, for all the preventions and solutions the article, including its sidebar “Keeping Ants Away,” I failed to see a compelling argument why.

Maybe it’s just sheer numbers, but I don’t consider 10, 15, 25, or even 50 ants smaller than a grain of rice to be a problem in my kitchen. Why should I begrudge them eating what I cannot? If I saw more, I’d now that I’m the problem, leaving too much food around.

OK – so, if you are having a sudden influx of sugar ants, and it’s a bit much, your job then is to find out how they’re getting into your house. I know in my case, it’s through the patio door and through open windows, but if you have any gaps and cracks in your house, consider the sugar ants a symptom, and sealing the gaps and cracks a cure… which it especially is for energy efficiency.

Also, animal and insect populations go through boom and bust cycles. You might be having a boom year. Next year will be considerably less. Indeed, since I first noticed sugar ants, there have been one or two years in which I haven’t seen any.

Observing sugar ants with household and garden plants

I had an umbrella plant –  I don’t know what kind –for a long time. With the onset of spring, I put it out on the deck for its own good. It immediately produced new branches and leaves, and I noticed how the sugar ants laid eggs right at the junction on the underside of the growing terminal leaf, with several “nurses” remaining with the small clutches. They look like they are aphid farming. Yet the plant wasn’t damaged in any way.

Just when the plant was in reach of the balcony rails, along came my rabbits and ate a few of these terminal leaves, annihilating the eggs and their nurses in a few quick nibbles. The poor plant had to regroup and send out new terminal buds, to which the ants responded in kind again.

The bunny-attacked plant with the new growth seemed little worse for wear. It kept growing with no scar tissue from this “infestation.” And since then, I’ve noticed this behaviour with many other indoor and outdoor (especially flowering!) plants. Could this be a symbiotic relationship?

In 2007,  Mathews et al published a paper titled EFNs Enhance Biological Control of G. molesta (Environmental Entomology 36(2)) about the sugar secreted by peach tree leaves and how, if ants have access to the canopies of the trees, they competitively exclude (or predate upon) oriental fruit moths. They then become a biological pest control agent.

The moral of the story is, though this isn’t the same plant, and it isn’t the same ant, the view of “pest” needs to be more rigorously applied: are those sugar ants doing you any harm? Could they been seen as helpful?

For me, no harm, and helpful if they help keep my counter clean. While I’m definitely not creating an ant farm here, I observe as much household cleanliness as most people (and a good deal more than some), without being spray-bottle-obsessed. It just seems to me that sugar ants going about their business without undue intervention is an overall good, and I only need to put my fruit away.

So my recommendation is: keep your food out their way, keep your surfaces clean, check if you have a hidden gap that they seem to be entering by, and don’t begrudge the seasonality of these visitations. They’ll come and go.