Terro

Terro liquid ant baits are for the homeowner or property owner with ants coming into the house who wants the whole colony gone. Terro says its borax bait works slowly enough that worker ants carry it back to the queen and the rest of the colony. Outside, its granules, spray and dust treat the foundation so the next wave stays out.

Terro is based in Lancaster, Pennsylvania, and has been a brand since 1915, when it introduced Terro Liquid Ant Killer. It was acquired by Woodstream and sits in the Woodstream family of brands. The line now runs to liquid ant baits, aerosol sprays, perimeter granules, glue traps and ant dust.

Start with bait inside

Set the liquid baits right on the trail: the counter edge, under the sink, the gap by the window where the ants come in. Terro’s advice is to place them near the space where the ants are active, and a bait a few feet off the trail sits untouched. Snip a vial tip clean with scissors instead of twisting it off, so the opening sits flat. The pre-filled bait stations go inside, and the outdoor liquid bait stakes push into the soil where ants come up along the foundation, a sidewalk crack or the edge of the patio. When ants are coming in from outside, run both. Expect more ants for the first day or two, because they’ve found the food and they’re recruiting.

Leave the trail alone for a week

The mistake that ruins the most bait jobs is spraying. Terro advises against hitting swarming ants with a contact killer while you bait, and the reason is simple: every ant you spray is one that won’t carry bait home. Keep the baits in place, keep the spray can in the garage, and bait inside for at least a week before you treat anything outside.

Carpenter ants: go by the label

The ants that tunnel into wood framing are a different job from the ones on the counter, and the label tells you which Terro products cover them. The Ant Killer Plus granules list Black Carpenter and Florida Carpenter ants by name, alongside Cornfield, Argentine and other nuisance ants. The Outdoor Ant Killer Spray names carpenter ants, and Terro says its waterproof dust protects against fire and carpenter ants. If you find sawdust-like debris under a window sill or along a baseboard, that points to a nest in the wood; start with the granules along the foundation.

Granules along the foundation

Ant Killer Plus is a lambda-cyhalothrin granule that kills listed insects on contact and leaves residual repellency. Before you shake it out, rake leaf litter away from the house and cut back any plants touching the foundation. Lay a 3 to 10 foot band along the foundation straight from the bag, no spreader needed, and water lightly right after.

The band only works on ants that walk across it, so keep it tight to the house where anything headed inside has to cross. For an ant hill in the lawn, put one to two teaspoons over and around it, and if the soil is dry, water lightly first to bring the ants up. Keep the high-pressure hose off treated ground, since a hard spray can push the colony to move. Large or established colonies may need a repeat application, on the schedule the label gives.

The spray for spot work

The Outdoor Ant Killer Spray covers what the granule band can’t: a trail running up the siding, cracks and crevices, an anthill by the step, or a line along the building as a barrier. Its blast knocks insects down so they don’t scatter, and the spray expands on the surface and leaves an invisible residual deposit. Slip the extension tube onto the nozzle to reach up under the eaves. Rotate the dual-action nozzle fully into position and check the opening for blockage before you spray. Stand upwind, because Terro warns that blowback in wind can be harmful.

Dust for the gaps

Terro says its waterproof ant dust lasts up to 8 months, and the shaker puts down either a light sprinkle or a wide application. Use it in flower beds, in the basement and around the foundation, working it into the cracks and gaps where granules won’t stay put.

Other Terro lines on the shelf

Terro Garbage Guard kills insects drawn to trash cans by odors and food remnants and keeps them from coming back, Terro’s indoor spider glue traps catch spiders and other crawling insects inside the house, the fruit fly trap sits by the fruit bowl or the compost pail, and the fly ribbons hang in a garage, barn or shop where flies gather.

Outdoor spray and granules at a glance

Spec	Outdoor Ant Killer Spray	Ant Killer Plus
Model	T1700-6	T901-6
Package	One 19 oz aerosol can	3 lb resealable shaker bag
Where	Outdoor use only	Outdoor use only
Application	Spot treatment, cracks and crevices, foraging trails, anthills, perimeter barrier	Foundation band, lawns, spot treatment on ant hills
Performance	Reaches up to 10 to 15 ft	Kills insects in 24 hours
Carpenter ants on label	Carpenter ants	Black Carpenter, Florida Carpenter
Other pests listed	Asian lady beetles, boxelder bugs, cockroaches, crickets, spiders, sowbugs	Fire ants, cockroaches, crickets, earwigs, fleas, millipedes, silverfish, sowbugs

Frequently Asked Questions

How does Terro ant bait work?

Ants treat Terro liquid ant bait as food. They fill up on it and pass it mouth to mouth back at the nest, so the borax reaches ants that never leave it. Terro says its baits kill the entire colony, including the ants you don’t see. While the bait works, keep crumbs, pet food and spilled juice cleaned up so the bait is the best meal on the trail.

How long does it take Terro ant bait to kill the ants?

It isn’t meant to kill fast. Expect more ants at the bait for a few days, then fewer as the colony dies off. A big colony can empty a station before it’s done, so check the baits every day or two and put out fresh ones until ants stop showing up.

How long do Terro ant baits last once they’re set out?

A liquid bait only works while it’s wet and the ants are still feeding on it. Replace a station that’s empty or has dried and crusted over, because dried bait doesn’t draw them anymore. Keep open baits out of direct sun and away from heat registers, where they dry out fastest.

How do you use Terro ant killer on fire ants?

Fire ants need more than the teaspoon or two for an ordinary ant hill. For Terro Ant Killer Plus, Terro calls for half a cup of granules over each mound, spread two feet around it. Then soak each treated mound area with at least a gallon of water from a watering can, not a hard hose stream, so the colony doesn’t move.