In this new world, a 'spider' is no longer a moderately undesirable house-guest, but a terrifying murderous Deviant.
Stardust has caused these infected spiders to swell to many times their ordinary size. It can easily pin a person to the ground with its eight, strong legs.
And the worst part? You never know when or where it will decide to show up next.
The main component of spider silk is protein, which Stardust needs to replicate itself. When infected with Stardust, the spider starts to produce large amounts of Stardust in its abdomen and starts pulsing as though powered by its own bluey-purple heart.
The spider's abdomen will continually swell until it takes up almost its entire body mass. If you can break this abdomen open, a large quantity of highly toxic liquid Stardust will spew out.
Perhaps the only upside is that, once infected, the spider loses its ability to make webs, which really cuts down the amount of time you need to spend dusting.
Gotta look at the bright side...