Quick Identification Guide for Common Army Ant Varieties

Army ants are among the most fascinating and aggressive insects in the natural world. Known for their nomadic lifestyle, massive coordinated raids, and extraordinary strength, these ants have intrigued entomologists and nature enthusiasts alike. However, identifying different varieties of army ants can be challenging due to their similar appearances and behaviors. This guide provides a quick and effective method to identify some of the most common army ant varieties by focusing on their physical characteristics, behavior, habitat, and geography.

What Are Army Ants?

Army ants belong primarily to the subfamily Dorylinae (in the Old World) and Ecitoninae (in the New World). They are known for their large colonies that move constantly in search of food, unlike many ants that build permanent nests. Their raids can include thousands or even millions of individuals, overwhelming prey with sheer numbers.

Key Features to Look For When Identifying Army Ants

Before diving into specific varieties, here are some general features to observe:

• Size: Worker army ants vary from very small (3-5 mm) to quite large (up to 20 mm or more).
• Color: They range from pale yellowish-white to deep brown or black.
• Mandibles: Their jaws are often large, sharp, and adapted for gripping prey.
• Antennae: Usually elbowed with a defined number of segments.
• Behavior: Observe if they form distinct raiding columns or swarm raids.
• Geographical Location: Many species are region-specific.

Common Army Ant Varieties

1. Eciton burchellii (New World Army Ant)

Identification:

• Size: Workers range from 5 to 13 mm; soldiers can be larger.
• Color: Yellow to dark brown.
• Mandibles: Large and sickle-shaped in soldiers.
• Behavior: Known for massive swarm raids; workers form impressive columns when hunting.

Habitat & Range:

• Found primarily in Central and South American rainforests.
• Prefers moist tropical forests and lowland areas.

Distinctive Traits:

• Raids are highly coordinated and can last several days.
• Known for “bivouac” nests made entirely from living ants linking their bodies together.

2. Dorylus spp. (African Driver Ants)

Identification:

• Size: Workers typically 10-15 mm; soldiers up to 25 mm.
• Color: Dark brown to black.
• Mandibles: Massive, scissor-like mandibles in soldiers used for defense and hunting.

Habitat & Range:

• Widespread throughout sub-Saharan Africa.
• Inhabit forest floors, savannas, and grasslands.

Distinctive Traits:

• Swarm raids can involve millions of ants marching through the forest floor.
• They are known as “driver ants” because they aggressively drive prey before them.

3. Neivamyrmex spp. (American Army Ants)

Identification:

• Size: Small to medium-sized workers (4-10 mm).
• Color: Typically dark brown or reddish-brown.
• Mandibles: Less pronounced than Eciton but still powerful.

Habitat & Range:

• Found throughout North, Central, and South America, especially in arid or semi-arid regions.

Distinctive Traits:

• Tend to have smaller colony sizes compared with Eciton species.
• Often forage at night or during cooler parts of the day.

4. Labidus coecus

Identification:

• Size: Workers about 5-8 mm long.
• Color: Pale yellowish-white body with darker head region.
• Mandibles: Sharp but more slender compared to other army ants.

Habitat & Range:

• Tropical rainforests in Central and South America.

Distinctive Traits:

• Specializes in preying on other ants and termites.
• Forms ephemeral bivouacs but less conspicuous due to lighter color.

Additional Identification Tips

Observe Mandible Shape

The shape and size of an army ant’s mandibles can provide critical identification clues:

• Sickle-shaped mandibles typically indicate Eciton species.
• Scissor-like mandibles point toward Dorylus species, especially the large African driver ants.

Behavior Patterns

Army ants’ hunting strategies differ slightly:

• Eciton species create dense swarm raids that cover entire forest floors.
• Dorylus tend to move in columns that can appear like rivers of ants sweeping through vegetation.

Noticing whether the ants form a huge swarm or a more linear column helps narrow down the genus.

Worker Polymorphism

Some army ants exhibit polymorphism, workers come in different sizes within the colony:

• Eciton burchellii has clear minor workers and major soldiers.
• Dorylus also shows pronounced size variation aiding identification.

Pay attention to whether you see uniform-sized workers or a mixture of sizes.

How to Safely Observe Army Ants

Army ants are powerful predators but generally don’t attack humans unless provoked. When identifying them:

1. Keep a safe distance from raiding columns or bivouac nests.
2. Avoid disturbing large colonies, army ant bites can be painful.
3. Use a magnifying glass or macro lens on your camera to get detailed views without touching them.

Summary: Quick Reference Points

Conclusion

Army ants are diverse and often specialized predators with intriguing behaviors adapted for their environment. By paying close attention to size, coloration, mandible structure, behavior patterns, and geographical location, you can quickly identify common varieties like Eciton burchellii, Dorylus driver ants, Neivamyrmex, and Labidus coecus. Whether you’re a hobbyist naturalist or an aspiring entomologist, understanding these traits allows you to appreciate the incredible complexity behind these tiny yet formidable hunters.

For those interested in further study, consider using field guides specific to your region or consulting entomological resources that provide detailed morphological keys for army ant genera and species. Remember always to respect wildlife habitats when observing these fascinating insects!