Temnothorax exilis

Quick Summary

• Difficulty: Easy
• Origin & Habitat: Mediterranean region, from Portugal and Spain to Turkey, including Corsica, Sardinia, Sicily, Crete, Malta, and Greece. Inhabits dry, rocky, open habitats with Mediterranean scrub (phrygana), always in sunny localities ^[1][5].
• Colony Type: Facultatively polygynous, colonies can have a single queen (monogyne) or multiple queens (polygyne) ^[1][5]. Some populations may be obligatorily monogynous ^[6].
• Size & Growth:
  • Queen: ~4-5 mm (inferred from Temnothorax genus)
  • Worker: ~3-4 mm (inferred from Temnothorax genus)
  • Colony: Up to a few hundred workers (typical for Temnothorax)
  • Growth: Moderate
  • Development: 6-10 weeks (estimated, based on typical Temnothorax development) (Development depends on temperature, warmer conditions within the Mediterranean range speed it up.)
• Antkeeping:
  • Temperature: 20-26°C, they naturally live in warm Mediterranean climates and can handle short periods of higher temperatures ^[7]. Provide a gradient if possible.
  • Humidity: Low to moderate. They prefer dry nesting sites. Keep the substrate moderately dry, never waterlogged. Offer a small water source in the outworld.
  • Diapause: Yes (inferred from Mediterranean climate), a winter rest period of 2-3 months at 10-15°C helps maintain colony health and spring reproduction.
  • Nesting: Naturalistic setups work best, they nest under stones or in rock crevices. Use a flat stone setup, Y-tong nest with narrow chambers, or a plaster nest that stays dry. Chambers should be scaled to their small size.
• Behavior: Generally peaceful and non-aggressive. Workers are small, active, and forage individually for nectar and tiny prey. They are documented pollinators of orchids in Spain ^[8]. Their small size (3 mm) makes them escape risks, use fine mesh on all vents. They are hosts for the parasitic ant Chalepoxenus sp. ^[9] and the fungus Myrmicinosporidium durum ^[10].
• Common Issues: escape prevention is critical due to their 3 mm size, use fine mesh and tight lids, colonies may fail if kept too humid, they prefer dry Mediterranean conditions, wild colonies may carry parasites like Myrmicinosporidium durum that can affect survival ^[10], initial colony growth can be slow, first workers may take weeks to appear, colour variation in captive colonies is normal, wild populations range from yellow to black

Housing and Nest Setup

Because Temnothorax exilis is tiny (workers about 3 mm), you need housing scaled to their size. In the wild they nest in soil under medium rocks or in rock crevices, always in sunny spots ^[1][5]. For captivity, use a flat stone placed on a layer of soil or plaster, that mimics their natural nest site. Y-tong (AAC) nests with narrow chambers also work. Keep the nest dry to moderately humid. Temperature should be around 20-26°C, with a gradient if possible ^[7]. Escape prevention is crucial: use fine mesh on all vents and make sure lids fit tightly. A small outworld for foraging completes the setup.

Feeding and Diet

Like most Temnothorax, T. exilis is omnivorous. Offer sugar water or honey (change regularly) and protein a couple of times a week, small insects like fruit flies, pinhead crickets, or crushed mealworms work well. They have been seen visiting flowers and pollinating orchids in Spain ^[8]. Remove uneaten prey after 24 hours to prevent mold. Since they are small, make sure prey items are small enough to carry or are crushed.

Temperature and Seasonal Care

This is a Mediterranean species that prefers warm, dry, sunny habitats ^[2]. Keep them at room temperature (20-26°C). They can tolerate short periods of higher temperatures but not sustained heat. During winter, give them a diapause period of 2-3 months at 10-15°C, this mimics the cool Mediterranean winter and helps keep the colony healthy, triggering spring growth. Place the nest in a cooler room or a refrigerator set to the right temperature. Ensure the nest stays dry during diapause.

Colony Founding

Founding behavior for T. exilis is not documented in the research. Based on typical Temnothorax patterns, queens are likely claustral (seal themselves in a chamber and raise the first workers without feeding). The first workers (nanitics) will be smaller than normal. Avoid disturbing the founding queen. Colonies can be monogyne or polygynous in the wild ^[1][5], so you may be able to keep multiple queens together if they accept each other.

Health and Common Problems

Watch for the fungal parasite Myrmicinosporidium durum, which infects T. exilis in Italy ^[10]. Infected workers look normal but carry spores visible through the body wall. The fungus shows up in late summer and fall, and infected ants often die after hibernation. Keep the nest dry, over‑humidity is the biggest risk. Their tiny size means escape prevention must be perfect: use fine mesh (0.5 mm or smaller) on any ventilation. Colour variation in your colony is normal and not a health concern.

Behavior and Temperament

Temnothorax exilis is peaceful and non-aggressive. Workers forage individually and are active during the day. They use a modified stinger to smear venom (smear defense), typical of the tribe Crematogastrini. They do not sting. They are known to pollinate orchids ^[8] and serve as hosts for the parasitic ant Chalepoxenus sp. ^[9]. When disturbed, they do not swarm aggressively but may run away. Their small size makes them easy to keep, but escape prevention is essential.

Frequently Asked Questions

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References