The label is the law. Rates and restrictions below are taken from the product labels listed under Sources. Your product's own label governs; read it before you mix or apply. Mixing calculator · Disclaimer
- Active ingredient
- Sodium tetraborate decahydrate (borax)
- Chemical class
- A borate. IRAC places borax in Group 8D, the borates, within its miscellaneous non-specific (multi-site) inhibitors.[2]
- Mode of action
- IRAC Group 8D: Miscellaneous non-specific (multi-site) inhibitors: borates[2]
- Signal word
- TERRO Ant Killer II (also sold as TERRO Liquid Ant Baits, Outdoor Liquid Ant Bait Stakes and PCO Liquid Ant Bait): Caution[1]
Which ants it works on, and which it doesn't
The label names Argentine, ghost, cornfield, pavement, acrobat, white-footed, little black, odorous house, crazy and big-headed ants, plus other sweet-eating ants.[1]
It specifically excludes fire ants, pharaoh ants, carpenter ants and harvester ants. If one of those is your problem, this bait is the wrong tool.[1]
Diluting it for big infestations
Pest control operators may thin the bait to a 1% borax level (1 part bait to 5 parts water) for very large multi-queen colonies, then a 2% mix (1 part to 2 parts water) if ants persist. Once ant numbers drop sharply, the label says to stop diluting.[1]
Where it is used
Set bait right on ant trails and where you see ants: sink and tub edges, window sills, under food cabinets, along baseboards and in corners. The label's advice is not to skimp, because more placements work better.[1]
Since many invading ants nest outdoors, put some bait outside near the spots where they come in. Bait Bullets can line the foundation every 5 to 10 feet as a perimeter defense.[1]
Expect a crowd at first; that is the bait working. Keep fresh bait on every placement, leave the ants alone, and allow up to two weeks for full control.[1]
After the ants are gone, the label says to swap in new pre-filled baits or stakes every 3 months to keep them from coming back.[1]
Products and registrations
| Product | Registrant | EPA Reg. No. | Active % | Formulation | Signal word |
|---|---|---|---|---|---|
| TERRO Ant Killer II (also sold as TERRO Liquid Ant Baits, Outdoor Liquid Ant Bait Stakes and PCO Liquid Ant Bait)[1] | Senoret Chemical Company, Inc. | 149-8 | 5.4% | liquid bait (bottle, pre-filled bait stations and stakes) | Caution |
Safety and environmental hazards
People
Signal word CAUTION, and keep out of reach of children. The label tells you to put bait where children and pets can't get to it and to keep it away from food and feed.[1]
Pets
Bait placements belong in spots pets cannot reach, and the label says not to store the product where animals can get to it.[1]
Bees and pollinators
The label carries no bee or pollinator statement. The bait sits in small stations or on cardboard where foraging ants find it.[1]
Fish and water
Don't contaminate water, food or feed when storing or throwing it away. Never pour leftover bait down any indoor or outdoor drain; call your local solid waste agency about a partly full container.[1]
Common questions
- Is TERRO liquid ant bait the same as boric acid?
- No. Its active ingredient is sodium tetraborate decahydrate, which is borax. IRAC lists borax and boric acid separately, though both fall in Group 8D, the borates.[1][2]
- Why are there more ants after I put out TERRO?
- The label says ants first arrive in large numbers and then disappear. Workers carry the liquid back to feed the colony, so keep bait stocked and let them feed.[1]
- Can I use TERRO in a restaurant kitchen?
- Not in edible product areas of food handling businesses, or in serving areas while food is exposed. The label allows other areas of restaurants and many other buildings.[1]
Sources
- U.S. EPA Pesticide Product Label System, “TERRO Ant Killer II master label label, EPA Reg. No. 149-8 (EPA-stamped, Jan. 20, 2026).” www3.epa.gov/pesticides/chem_search/ppls/000149-00008-20260120.pdf (accessed 2026-10-06)
- Insecticide Resistance Action Committee, “IRAC Mode of Action Classification Scheme, Version 11.5 (Feb. 2026).” irac-online.org/documents/moa-classification/ (accessed 2026-10-06)