Hello? Anyone home? Can someone please declare Marshall Law?

I just want to confess, first off, that when I first typed that last sentence I initially typed 'Martial Law,' which makes me realize that in the action movie in my brain, Steven Seagal is definitely a leading man. 

Because I feel like this news is too important to be succeptable to the TL;DR zone, we're going to do this 4th-grade-news-reporter/birthday party invite style. Please stay informed:

Who: An invasive species of giant, deadly, predator-less African Snails, A.K.A. the fourth horsemen of the Apocalypse.

What: Are going to kill us, maybe.

Where: Well, it will probably start in Australia, since that's where one was recently found in a shipping container at the point of Brisbane.

When: Either never or soon? The scientists are "hoping it was the only one on board!" I hope so too, since these baseball-sized, nightmarish armored slugs which eat the sides off of houses, kill crops and carry meningitis which they can transmit to humans lay 1,200 eggs a year. 

Why: