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Pheidole rhea

Giant Big-Headed Ant

Pheidole rhea
Intermediate level
🛒 Shop colonies and kits

Photo: Jake Nitta, via iNaturalist, licensed under CC BY 4.0.

🐜 At a glance

  • Origin: Arizona, New Mexico, Mexico; grassy, rocky upland slopes; nests under rocks

  • Nest temperature: 26–30°C; heater at 28°C; never above about 32°C

  • Outworld temperature: 18°C night, up to 28°C day; by day like the nest or a degree or two cooler

  • Humidity: Nest 50–70%; outworld about 50%, never watered

  • Winter: No full hibernation; optional rest 18–20°C for about 2 months; never below 15°C

  • Move to a nest: 50+ workers; A queen on her own too

  • Size: Queen about 16–18 mm; minors 3–4.5 mm, majors 5–10 mm, supermajors 11–13 mm

  • Colony: One queen; tens of thousands of ants when mature

📖 About this species

The giant of the big-headed ants, with minors, majors and huge-headed supermajors, from the uplands of Arizona, New Mexico and Mexico. A North American ant, not sold by Best Ants UK and possibly illegal or impossible to import to the UK.

🍯 Feeding

  • Proteins: Protein Jelly (keep in the fridge) or Cricket Mash. Live food only for established colonies: scalded, cut in half, never smaller, no mealworms

  • Carbohydrates: organic Ant Honey or Ant Nectar, far better than sugar water or home-made mixes; small drops

  • Seeds: important; our harvester seed mix on tin foil or a feeding dish, never on the substrate (sprouted seeds are harmful)

  • Twice a week, small amounts, outworld only; leftovers out after 2 days. Founding queen: a tiny drop of protein jelly on tin foil once a week

💧 Watering the nest

  • Distilled or purified water only. Never tap, rain or bottled mineral water, even boiled (mould and fungus).

  • Pipette a few drops through the watering hole; stop when 1–2 drops appear inside. About once a week, or when the meter drops below 50%.

  • Never water the outworld; keep it at about 50% humidity. A watering test tube in the outworld: never let it run dry, this species dries out quickly.

🏠 Setting up the ant farm

  • A7 Plus ant farm kit only (built-in digital meter); plan for more room as the colony grows fast

  • Advanced Heating System Small 4W under one quarter of the nest, opposite the watering area, set to 28°C; warm the outworld too

  • Daylight, never direct sunlight; away from windows, radiators, vibrations, speakers and kitchens

  • Escape risk: high for the minors. PTFE Fluon band on the top inner edge of the outworld lid, reapplied every 2–4 weeks

💡 Good to know

  • North American ant: not sold by Best Ants UK, and possibly illegal or impossible to import to the UK. We never encourage importing ants

  • Barely grows at UK room temperature; supermajors crush seeds the others can't open. No rest in a queen's first year

  • Never release it. Can't keep it? See our ant adoption page

⭐ Golden rules | Never break these

  • 🚫 Never put ants in a fridge, shed or garage, and never expose them to abrupt temperature changes.

  • 🚫 Never use gel ant farms, Ytong or concrete nests, or DIY nests.

  • 🚫 Never use tap, rain or mineral water, even boiled.

  • 🚫 Never move a colony into a nest too early, and never tip or shake ants out of their tube.

  • 🚫 Never release ants into the wild. If you can no longer keep a colony, visit our ants adoption page and ask us whether we can adopt it.

🛒 Recommended for this species

📚 These care notes cover the essentials only. Please read the full ant farm setup guide and our Pheidole rhea care guide from A to Z. Questions? Message us through our contact form and we will be happy to help. 💚

Written and reviewed by the Best Ants UK team, keeping ants since 1997.

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