Let's talk about what inspired the nighty Hivemind! The only good bug is a dead bug.
The 41st millennium is fraught with peril for the humans of the Imperium, both from traitors within their own communities and xenos threats from beyond the stars, to say nothing of daemonic incursions. But perhaps the most terrifying threat to Imperial lives is the Tyranid Hivefleets, for where all other enemies fight for conquest, subjugation, or some other unseen game, the Tyranids view all life simply as biomass to be consumed. Even their injured warriors are devoured to serve as fuel for the endless biological war machine, sweeping across planets in a tide of fangs and claws until it is nothing but a barren husk.
They cannot be reasoned with, they cannot be bought, and perhaps most terrifying of all, they have no presence in the Warp, causing a psionic nightmare to descend on any psykers that happen to be in their path. Worse still, the citizens of the Imperium aren't the only poor saps that have to deal with creatures like this, and similar alien creatures have hunted the silver screen, the bookshelf, and even your own garden! Here are a few of the places Tyranid-like creatures have shown up ...