Rats love food. Garbage is food for them, but so are warehouses for foodstuffs and cargo holds. Rats are well-evolved urban creatures. You find them where you find humans because humans love to store up food.
Please remember that it's just a metaphor. Even the best metaphors break down and lose their usefulness when stretched to far.
And now to continue my derailleur:
The King James Bible was commissioned after a rejection by the people of the Bishop's Bible then in use by the Church of England.
The Bishop's Bible was a response to the Geneva Bible. The Geneva Bible was an excellent translation into the English of the day, but the margin notes promoted Calvinism very strongly. The Church of England wasn't wholly committed to Calvinism, so they commissioned Bishop's Bible. The Bishop's Bible had it's own margins notes intended to explain to the people what the Bible meant.
The people didn't want margin notes telling them what the Bible meant. They wanted to read the Bible and decide for
themselves what it meant. And thus the King James Bible was commissioned.
And so, the King James Bible was in a way a
rejection of study bibles. I would very strongly caution anyone not to rely to greatly on the notes & articles in their study bibles.
I am very self indulgent when it comes to my collection of bible handbooks, bible dictionaries, commentaries, atlases, and other helps. But I haven't used a study bible as am daily bible in nearly 30 years.
I do keep a Thompson Chain Reference Study Bible in my preferred translation as a "traveling bible" if I go anywhere away from my library and I think that I might get asked to speak. One of the reasons I choose the Thompson Chain Reference Study Bible is that, while it has a truly
exceptional topical reference system that lists topics and collects verses that pertain to that topic, it makes no attempt to say what the meanings are. You are left to read the verses and decide for yourself.