Strumigenys castanea

Quick Summary

• Difficulty: Expert
• Origin & Habitat: Neotropical region: Colombia (Chocó), Venezuela, and Brazil (Bahia). Found in wet forest, living in leaf litter and decaying wood ^[1][2][3][4].
• Colony Type: Unknown – colony structure has not been directly studied. Keepers should assume single-queen colonies until more information becomes available.
• Size & Growth:
  • Queen: Unconfirmed, the queen has not been described in scientific literature
  • Worker: 1.9–2.0 mm total length ^[4]
  • Colony: Unknown – typical dacetine colonies are small, likely under 100 workers, but no firm data for this species
  • Growth: Slow – based on related Strumigenys species
  • Development: Unknown – not documented for this species, expect slow development based on genus patterns (First workers (nanitics) will be very small. Keep conditions stable and avoid disturbing the queen during founding.)
• Antkeeping:
  • Temperature: Keep warm and stable, roughly 22–26°C. These are tropical ants that cannot tolerate prolonged cold ^[1].
  • Humidity: High humidity is essential. Keep the nest substrate consistently damp but not waterlogged. Provide a moisture gradient by keeping one area very humid and another slightly drier. These ants come from wet forest environments ^[1][4].
  • Diapause: No – this tropical species does not need winter cooling. Maintain warm conditions year-round.
  • Nesting: Use test tubes for founding, then move to Y-tong (AAC), plaster, or soil nests with very high humidity. Small outworlds with damp leaf litter and a constant springtail population are ideal. Escape prevention is critical – every gap must be sealed with fine mesh or fluon.
• Behavior: These ants are peaceful and non‑aggressive. They are specialized predators that slowly stalk springtails and other tiny arthropods. Their sting is functional but not medically significant. Workers move slowly and prefer to stay hidden in humid microhabitats. Escape prevention is vital – at 2 mm they can squeeze through gaps invisible to the naked eye.
• Common Issues: escape prevention is critical – at just 2 mm they fit through gaps that look sealed, so use fine mesh and fluon on all openings, high humidity is non‑negotiable – dry conditions cause rapid colony decline and death, specialized diet makes them dependent on a reliable supply of live springtails, they often refuse standard ant foods, slow growth tests patience – colonies remain tiny for many months and may stay under 20 workers for over a year, wild‑caught colonies may carry parasites or suffer from collection stress, quarantine new colonies carefully

Housing and Setup

Strumigenys castanea needs a setup that keeps humidity high and prevents escapes. Start with a test tube with a water reservoir separated by a cotton plug. Keep the whole tube inside a larger container with damp soil or paper towel to maintain humidity ^[4]. Once the colony has a handful of workers, you can move them into a Y‑tong (AAC) nest – this material holds moisture well and lets you watch the ants. The nest chambers should be only a few millimeters tall so the tiny ants can use all the space. Connect a small outworld (a few centimeters across) – a large outworld makes it harder for them to find food. Use fine mesh (0.2 mm holes or smaller) over any ventilation, and apply fluon to the outworld walls. Because these ants are only 2 mm long, gaps you can barely see are open highways for escapees. Add damp leaf litter or moss to the outworld to keep humidity up and provide hunting grounds for springtails ^[1][4].

Feeding and Diet

Feeding is the hardest part of keeping this species. They are specialized predators that almost exclusively eat live springtails (Collembola). Their mandibles are built to snap shut on fast‑moving, tiny prey. Standard ant foods like sugar water, honey, or seeds are completely ignored. You must culture your own springtails – several species work, but the small white ones (like Sinella curviseta) are ideal because they match the prey size these ants hunt. Offer small springtails (under 2 mm) every 2–3 days. Place them directly into the outworld near the nest entrance and watch the workers hunt. Remove any springtails after 24 hours to prevent fungal growth. Experimentally, some colonies accept very small pieces of mealworm, but don’t rely on this. Never leave uneaten protein in the nest – it rots quickly ^[4].

Temperature and Humidity

This tropical ant needs warm, stable conditions. Keep the nest at 22–26°C year‑round – avoid dropping below 20°C for extended periods. A gentle heat mat on one side of the nest can create a gradient, but do not exceed 28°C. Humidity is the most critical factor. The nest substrate must stay consistently damp but not waterlogged. A good method: use a Y‑tong nest with a built‑in water reservoir that you refill regularly, or use a test tube with a cotton plug that stays moist. Provide a gradient – one corner of the nest can be slightly drier (around 60% relative humidity) while the main chamber is very humid (80–90%). In practice, you can achieve this by having a water reservoir on one side only. Never let the nest dry out – even a few hours of dry air can kill workers and cause the colony to collapse. Keep the outworld humid as well by adding damp moss or a piece of wet sponge ^[1][4].

Colony Development

Colony growth is slow and patience is essential. The queen has never been described, so everything about founding is based on related Strumigenys. Expect a single queen to raise the first batch of tiny workers (nanitics) from her own reserves. These first workers will be very small and may not hunt effectively – the queen may feed them by trophallaxis. As the colony reaches a few workers, you can start offering live springtails. A mature colony likely stays under 100 workers, and after 2–3 years you might see 40–60 ants. Don’t expect a massive colony, focus on keeping them healthy and reproducing. Growth rate is slow even under ideal conditions. Any disturbance during founding can cause the queen to abandon the brood, so check only once a week ^[4].

Frequently Asked Questions

Report an Issue

The current care sheet is based fully on literature. See inconsistencies, or something that's incorrect? Please report here, it will be resolved after review from an admin. Contributing to the blogs tab also helps providing information, to make us be able to further improve the caresheets. Thank you for your support!

References