[2] Called a "pocket universe" story by The Encyclopedia of Science Fiction,[3] "Giant Killer" is told from the point-of-view of a colony of mutants living in a spaceship.

Though they are eventually (in the final sentence) revealed to be rats, they are obviously sentient lifeforms: they have a culture, complete with marriage, seers, governmental structures, specialized safety equipment, and ritualized combat.

They are illiterate, albeit: they marvel as the giants make black marks on "skin," which they perceive as some inscrutable form of "sorcery."

Much is made of the mutants' efforts to understand the giants' fascinating world, including such locales as the Place-of-Life-Which-Is-Not-Life, obviously the robotics laboratory.

In the 1967 novel "Contraband from Otherspace", Chandler's character John Grimes travels to an alternate history timeline where mutant rats have taken over the Rim Worlds and cruelly enslaved their human population.