However, you could use a general term like:
* A colony of caterpillars
* A group of caterpillars
* A brood of caterpillars
You can also use descriptive terms based on the context, like:
* A swarm of caterpillars (if they are moving together)
* A cluster of caterpillars (if they are gathered in one place)
* A feeding frenzy of caterpillars (if they are eating)
Ultimately, the best term depends on the specific situation and the desired effect.