What does vermin mean?

You are correct!

From our dictionary:

ver•min

Pronunciation: (vûr'min), [key]
n.,
pl. ver•min.

1. noxious, objectionable, or disgusting animals collectively, esp. those of small size that appear commonly and are difficult to control, as flies, lice, bedbugs, cockroaches, mice, and rats.
2. an objectionable or obnoxious person, or such persons collectively.
3. animals that prey upon game, as coyotes or weasels.