What is the collective noun for hoodlums?

There isn't a widely accepted or commonly used collective noun for hoodlums.

Here are some options you could use, depending on the context and desired effect:

Informal:

* A gang of hoodlums

* A pack of hoodlums

* A bunch of hoodlums

More evocative:

* A rabble of hoodlums

* A horde of hoodlums

* A crew of hoodlums

Ultimately, the best choice will depend on the specific situation and the tone you want to convey.