Scientific illustration of Polyrhachis armata (Armed Spiny Ant) - showing key identification features including head, thorax, and gaster.

Armed Spiny Ant

Polyrhachis armata

Monogynous Non-Parasitic Queen No Gamergate
Sci. Name
Polyrhachis armata
Subgenus
Myrmhopla
Tribe
Camponotini
Subfamily
Formicinae
Author
Le Guillou, 1842
Common Name
Armed Spiny Ant
Distribution
Found in 11 countries
Queen Activity
From January to December
Peak Time
11:00
AI Identifiable
try →

Introduction

Polyrhachis armata is a distinctive spiny ant native to Southeast Asia, ranging from India through the Philippines, Thailand, Malaysia, Indonesia, and into southern China . Workers are robust ants measuring approximately 9-11 mm in total length with a black body and distinctive spines on the thorax and petiole . They belong to the subgenus Myrmhopla and are known for their arboreal nesting habits, using silk to construct nests in trees and vegetation . This species is a primary forest specialist and is rarely found in disturbed areas or secondary growth . A unique feature of Polyrhachis armata is its defensive mechanism: when threatened, workers secrete a bubble acid foam from the tip of their abdomen .

Loading distribution map...

Status by country, from Kass et al. 2022 & Wong et al. 2023

Native Invasive Introduced (indoor) Intercepted Unknown
2000 - 2026

Quick Summary

  • Difficulty: Medium
  • Origin & Habitat: Southeast Asian tropical rainforests, from India through the Philippines, Borneo, Sumatra, Java, Thailand, Vietnam, Malaysia, Singapore, Laos, Cambodia, and southern China. Found primarily in primary lowland dipterocarp forests and canopy environments [1][7].
  • Colony Type: Colony structure is unconfirmed. Based on genus patterns, likely single-queen colonies.
  • Size & Growth:
    • Queen: Size data unavailable
    • Worker: Approximately 9-11 mm [4][5]
    • Colony: Up to 500 workers (estimated)
    • Growth: Moderate
    • Development: Estimated 6-8 weeks at optimal temperatures [9] (Development time is not directly documented, estimates based on typical Polyrhachis patterns.)
  • Antkeeping:
    • Temperature: Keep warm and stable, roughly 24-28°C, based on tropical rainforest habitat [9].
    • Humidity: Keep nest substrate consistently moist but not waterlogged, with some drier areas available, as they are from humid environments [9].
    • Diapause: No, as a tropical species, they do not require hibernation [9].
    • Nesting: Arboreal ants that naturally nest in trees using silk. In captivity, provide naturalistic setups with plants or Y-tong nests with climbing structures [6].
  • Behavior: Workers are generally calm but will defend themselves by secreting bubble acid foam when threatened [8]. They are good climbers and may attempt to escape if housing is not secure. Escape prevention should be moderate due to their size and climbing ability.
  • Common Issues: primary forest specialist may struggle in suboptimal captive environments., arboreal nature requires vertical space and climbing structures., defensive foam secretion can be startling but is harmless to humans., sensitive to temperature drops, keep consistently warm., may be difficult to establish if wild-caught from degraded habitats.
Queen Ant Activity Analysis 376 observations
29
Jan
35
Feb
Mar
25
Apr
38
May
21
Jun
28
Jul
23
Aug
39
Sep
42
Oct
46
Nov
32
Dec

Polyrhachis armata exhibits a clear seasonal activity window. Peak activity is concentrated in November, with the overall period spanning January to December. This extended season suggests multiple flight events or varying conditions across its range.

Queen Activity by Hour 376 observations
7
00:00
01:00
02:00
03:00
04:00
05:00
9
06:00
20
07:00
27
08:00
28
09:00
32
10:00
35
11:00
28
12:00
19
13:00
16
14:00
30
15:00
25
16:00
22
17:00
18:00
12
19:00
14
20:00
10
21:00
10
22:00
12
23:00

Polyrhachis armata queen activity peaks around 11:00 during the late morning to early afternoon. Activity is spread across a 17-hour window (07:00–23:00). Times may be influenced by human observation patterns.

Housing and Nest Setup

Polyrhachis armata is an arboreal species, so provide a setup with vertical space for climbing. Use naturalistic arrangements with live plants, branches, or leaves that they can bind with silk [6]. Alternatively, a Y-tong nest with multiple chambers works well. Add materials like cotton or fabric for silk binding. Ensure the setup is secure to prevent escapes.

Feeding and Diet

These ants are omnivorous. Offer sugar water or honey constantly for energy, and provide protein sources like small insects 2-3 times per week [9]. Remove uneaten food after 24-48 hours to prevent mold.

Temperature and Humidity

Keep temperatures between 24-28°C consistently, as they are from tropical rainforests [9]. Maintain humidity by keeping the nest substrate moist but not waterlogged, with some drier areas available [9].

Behavior and Defense

Workers secrete a bubble acid foam from the abdomen when threatened, which is a unique defensive trait [8]. They are not aggressive but will defend their nest. Use standard escape prevention measures due to their climbing ability.

Colony Development

Colony growth is moderate. First workers may emerge in about 6-8 weeks at optimal temperatures, based on typical Polyrhachis patterns [9]. Provide adequate space as the colony expands.

Ecological Notes

Polyrhachis armata is a primary forest specialist, found almost exclusively in intact rainforest and absent from disturbed areas [7]. It can be host to the fungus Ophiocordyceps unilateralis in Asia [10][11]. This specialization means captive colonies may be sensitive to environmental conditions.

Frequently Asked Questions

How long does it take for Polyrhachis armata to have first workers?

Expect first workers in about 6-8 weeks at optimal temperatures of 25-28°C, based on typical Polyrhachis development patterns [9].

What do Polyrhachis armata ants eat?

They are omnivorous. Offer sugar water or honey constantly, and provide protein like small insects 2-3 times per week [9].

Do Polyrhachis armata ants need hibernation?

No, they do not need hibernation as a tropical species. Keep warm conditions year-round [9].

What size colony do Polyrhachis armata reach?

Colonies can reach up to 500 workers, based on estimated arboreal patterns [9].

Are Polyrhachis armata good for beginners?

They are rated medium difficulty due to needs for high humidity, warm temperatures, and arboreal setup [9].

What type of nest is best for Polyrhachis armata?

A naturalistic setup with plants or branches works best, as they are arboreal and use silk for nesting [6].

Why is my Polyrhachis armata colony struggling?

This species is a primary forest specialist and may struggle with low humidity, temperatures below 24°C, or suboptimal nesting materials [7].

Can I keep multiple queens together?

Colony structure is unconfirmed, it is not recommended to combine unrelated queens as polygyny has not been documented [9].

Where is Polyrhachis armata found in the wild?

Native to Southeast Asia, including India, Philippines, Borneo, Thailand, and southern China, in primary rainforest canopies [1][2][3].

What makes Polyrhachis armata unique?

They are spiny ants with arboreal silk nesting and a defensive bubble acid foam secretion [8][6].

Are Polyrhachis armata escape artists?

They are moderate escape risks due to climbing ability, use secure housing with tight lids [9].

When do Polyrhachis armata queens forage?

Queen activity of Polyrhachis armata typically occurs From January to December. Times may be influenced by human observation patterns.

What time of day are Polyrhachis armata queens most active?

Queen activity of Polyrhachis armata peaks around 11:00 during the late morning to early afternoon, with most activity between 07:00 and 23:00. Times may be influenced by human observation patterns.

Report an Issue

The current care sheet is based fully on literature. See inconsistencies, or something that's incorrect? Please , 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

Creative Commons License

This caresheet is licensed under CC BY-SA 4.0 .