A group of caterpillars is called an army.
Caterpillars, the larval stage of butterflies and moths, are voracious eaters, and when they gather in large numbers on a single plant or tree, the visual is dramatic enough to earn a suitably dramatic name.
What Is a Group of Caterpillars Called?
The standard and most widely used term is an army of caterpillars, evoking the image of a coordinated mass moving steadily across leaves and branches.
Where Did the Name Come From?
“Army” fits caterpillars for a very literal reason: certain species, like the fall armyworm (itself a caterpillar, not a worm), march in large, destructive groups across fields, consuming crops as they go, behavior that closely resembles an advancing military force. The term captures both the sheer numbers caterpillars can gather in and the methodical, plant-devouring efficiency of their movement.
Caterpillar Facts
- Habitat: Caterpillars are found wherever their host plants grow, from forests and fields to backyard gardens, since most species are tied to specific plant types.
- Social behavior: Many species are solitary, but some, like tent caterpillars and armyworms, gather in dense groups for feeding and protection.
- Diet: Almost exclusively herbivorous, caterpillars eat leaves, and some species can strip a plant bare in a matter of days when feeding in groups.
- Lifespan: The caterpillar stage typically lasts just 2-6 weeks before metamorphosis into a pupa.
- Distinctive: A caterpillar can increase its body mass thousands of times over during its larval stage, thanks to near-constant eating.
Example Sentences
- An army of caterpillars stripped the oak tree’s leaves in a matter of days.
- Farmers watched anxiously as an army of caterpillars moved across the field.
Other Names for a Group of Caterpillars
“Army” is the primary and most widely recognized collective noun for caterpillars.
Frequently Asked Questions
What is a group of caterpillars called?
A group of caterpillars is called an army, a nod to how some species march and feed in large, coordinated groups.
Why are caterpillar groups called an “army”?
Species like the fall armyworm move and feed in large groups that strip vegetation efficiently, resembling an advancing military force.
Do all caterpillars live in groups?
No, many caterpillar species are solitary; group behavior is more common in specific species like tent caterpillars and armyworms.
How much do caterpillars eat?
Caterpillars eat almost constantly and can increase their body mass thousands of times over before pupating.
Related: Collective Nouns for Insects