This slim, grim piece of b-movie trash (and believe me, I mean that in the most positive and respectful way) actually launched a sub-genre in the british horror novel industry - the mutant pet and/or pest novel. The next few years would see bookshelves stuffed with grue dripping books about killer cats, dogs, bats, crabs, slugs (yes, I said slugs), spiders, jellyfish, and assorted other nasties. For this alone Herbert's novel deserves some kind of special recognition.
The novel itself was written, by hand I believe, on a lark. In one interview Herbert even admitted to not even bothering to do a rewrite! The story is simple: giant mutant rats gobble down assorted victims as, in between the gruesome attacks, scientists and members of the government scratch their heads and wonder how to do away with the seemingly indestructable beasties. In what would grow to be a trademark storytelling style, Herbert lavishes as much character detail on the victims to be as he does on the actual characters. An essential book for animal on the rampage buffs and rodent lovers everywhere.