It’s a long story.
First of all, the zombie hamsters were created by rigging up surplus military material to nuke them back to life after they were frozen solid by the Mad Scientists of Mill Hill.
No, I am not making this up.
Second of all, the scientist in charge of hamster zombification was James Lovelock, who later originated the Gaia Hypothesis, for which he is alternately vilified and deified by the Global Warming is an Apocalypse/Global Warming is a Hoax crowd, depending on how literal-minded the reader happens to be at that particular moment.
Third, the Gaia Hypothesis itself was named by the man who wrote Lord of the Flies. Which gives one pause, especially if one is a happy hippie kumbaya life-in-harmony type. Maybe the “Red in Tooth and Claw Hypothesis” was taken?
Fourth, to obtain the components for the hamster zombification machine, Lovelock had to delve deeply into the Red Light district of London, an area whose denizens, it is claimed, held no charms for him. That’s our boy! I’m sure those spinster novelists who were responsible for the creation of the archetype of respectable “confirmed bachelor” would be proud of him.
Actually (fifth!), microwaving the hamsters was an improvement over what they were doing before, which was putting heated spoons on their chests until their hearts restarted. Was one of those Mill Hillers a freebaser, perchance?
In any case (sixth!), it’s a long, strange journey from reanimating cryorodents to inventing the Grand Unified Theory of Planet Earth. But once you realize that the central question is: what is life, the flight plan makes more sense.