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
- Metaflumizone (CAS 139968-49-3)
- Chemical class
- Semicarbazone; IRAC Group 22B voltage-dependent sodium channel blocker, a nerve-action group whose other subgroup, 22A, holds indoxacarb.[2][1]
- Mode of action
- IRAC Group 22B: Voltage-dependent sodium channel blockers: semicarbazones[2][1]
- Signal word
- Siesta Insecticide Fire Ant Bait: Caution[1]
Keeping bait away from water
Broadcast spreading is not allowed within 10 feet of lakes, rivers, streams, marshes, natural ponds or brackish water. Active mounds inside that buffer can still get the individual mound treatment.[1]
Sweep up or cover any spilled granules and keep them out of drains and open water.[1]
Freshness and rotation
Siesta is formulated in an oil bait. Air exposure can turn the oil rancid and make it less attractive to ants, so the label says to use an opened container within 3 months.[1]
Rotate Group 22B baits with fire ant products from other IRAC groups to slow resistance, as the label recommends.[1][2]
Where it is used
Put bait out when ants are foraging: early morning or late afternoon, with temperatures above 60°F. Skip soggy ground, heavy dew, or days with heavy rain expected within 12 hours.[1]
Don't water the granules in. Wait at least 12 hours before irrigating, since rain soon after application can weaken results.[1]
Leave the mound undisturbed while baiting, and hold off on contact insecticides for 7 days so workers can carry the bait home.[1]
Control can last up to 8 weeks or longer. If it seems to fade, reapply after 4 to 8 weeks, staying within 4 applications a year.[1]
Products and registrations
| Product | Registrant | EPA Reg. No. | Active % | Formulation | Signal word |
|---|---|---|---|---|---|
| Siesta Insecticide Fire Ant Bait[1] | BASF Corporation | 7969-232 | 0.063% | granular oil bait | Caution |
Label rates
| Product | Use | Pests | Rate |
|---|---|---|---|
| Siesta Insecticide Fire Ant Bait | Lawns, turf, landscaped areas, golf courses, parks, school grounds and outdoor areas around homes and other buildings | Imported and native fire ants | 2–3 oz product per 5,000 sq ft[1] That works out to 1 to 1.5 pounds per acre with a hand-held, walk-behind or motorized spreader. Around buildings, sprinkle a band about 1 to 2 feet wide along the foundation. |
| Siesta Insecticide Fire Ant Bait | Individual fire ant mounds, including mounds among container-grown plants | Imported and native fire ants | 1–2 oz product per mound[1] That is 2 to 4 level tablespoons scattered evenly 3 to 4 feet around the mound, never on top. Treat no more than 12 mounds per acre at one time. |
Safety and environmental hazards
People
Signal word CAUTION: harmful if absorbed through skin or swallowed, and may cause moderate eye irritation. Prolonged or repeated skin contact may cause allergic reactions in some people, so wash hands after handling.[1]
Pets
The label says to avoid direct exposure of animals to the granules. It allows use where horses and llamas are kept, provided they aren't used for food.[1]
Bees and pollinators
The label has no bee or pollinator statement; the product is a granular bait for ants.[1]
Fish and water
Toxic to fish and aquatic invertebrates. Metaflumizone can build up in aquatic and land animals and may affect reproduction in birds, mammals, reptiles and amphibians if misused.[1]
Common questions
- How does metaflumizone kill a fire ant colony?
- Worker ants pick up the bait and carry it into the mound as food. It is eaten and fed to the queen, and the label says the mound is then destroyed.[1]
- How much Siesta per mound?
- 1 to 2 ounces, or 2 to 4 level tablespoons, spread 3 to 4 feet around the mound rather than on top.[1]
- Can I water after putting down fire ant bait?
- Not right away. The label says not to water the granules in and to wait at least 12 hours before irrigating.[1]
Sources
- U.S. EPA Pesticide Product Label System, “Siesta Insecticide Fire Ant Bait label, EPA Reg. No. 7969-232 (EPA-stamped, July 22, 2020).” www3.epa.gov/pesticides/chem_search/ppls/007969-00232-20200722.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)