New York State IPM Program

Ants in your house? Throw them a party!

Not fond of ants in the kitchen? You are not alone. And even after you’ve cleaned them up, washed the countertop, swept away the crumbs and taken out the garbage — they just keep coming, looking for more.

It’s this time of year when ants invade homes looking for food, water and shelter. Where are they coming from — and how are they getting there?

At 1/16 to 1/8 inch long, this is one tiny ant. Photo credit Joseph Berger.

A number of ant species seem to specialize in homes. Among the most tenacious: the odorous house ant, Tapinoma sessile. You can tell it by its smell.  Just crush it in your fingers and give it a sniff.

What’s that smell? Some say it’s the smell of rotting coconut, but how many of us know the pleasure of a rotting coconut? Just call it pungent.

Odorous house ants are well adapted to the urban environment. In fact, being around man-made structures allows them to become the dominant ant species with enormous interconnected colonies. They invade homes and apartments through the smallest cracks and gaps, foraging for sweets. So keeping them out may be near impossible.

Pesticides and insecticidal ant baits are the most common forms of ant control. In IPM we almost never recommend spraying over other sound tactics. In the case of odorous house ants, spraying the foundation and soil around a structure can help. But it can also kill non-target insects.

Plus — it rarely kills the queen (an urban supercolony may have scores; even hundreds) and the colony might well live on.

Baiting for odorous house ants with sweet gel baits is an effective way to reduce the whole colony. Adult ants carried them back to the nest and fed to the larvae and queens — the beating heart of the colony.

You might choose to hire a professional who will identify the ant species (very important for baiting correctly) and place bait where ants are active. Or you might decide to use sweet boric acid bait from the hardware store. Either way there’s a critical step here.

…..  LET THE ANTS PARTY!  ….

Whatever the source — spilled food or bait station — ants do like to party. Invite yours with a sweet ant bait. Photo credit M. Potter, UKY.

If the odorous house ants accept the bait, more and more ants will show up for the feast. The more ants, the more bait they will transfer back to the larvae and queens. Let the party rage on! You could see dozens of ants, maybe hundreds.

Ignore them until at least the following day — and never spray an insecticide or cleanser on or near the bait. With professional-use baits, the disappearance of ants is quite dramatic. Boric acid baits will take a bit longer but are no less effective.

As always, before you use a pesticide, read the label and follow instructions. Once the party is over, clean up the remains with soap and water.

And remember, ants are like a sanitation department. They forage on what we leave behind, so keep those counters (and the sink, garbage can, compost bucket, microwave…) clean and free of food spills and crumbs. We best coexist with ants when we don’t invite them inside.

 

Author: Jody Gangloff-Kaufmann

Urban entomologist

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