I'll be honest this is mostly just because I dislike the word itself, but..
We currently have 5 questions (1 is on hold) using the vermin tag:
I think it's pretty clear that people using the tag view it as a pest-control tag. The problem is that we are supposed to be about Pets not Pests. I'm simply not interested in helping people get rid of animals they don't like.
My solution is that we get rid of the tag so that we can get rid of the obviously off-topic questions, and discourage more questions from happening in the future (hopefully).
I think that for the question to be on-topic here it will be able to be tagged with other tags such as safety if it's a case of pests causing the animal harm, or parasites if it's a a parasite such as a flea or tick.
Otherwise I think that we should make a tag for pest-control and make vermin a synonym. At the very least, I think we need to rewrite the wiki for the vermin tag so that it's more clear what it's supposed to be about.
Thoughts on this?