Now that's a hoot! Imagine an airplane sliding off the runways into the Med' there due to this? That's a lot of 'Nice French escargot' eh?!
Snails can also cause all sorts of havoc with cargo. While stationed at Andersen AFB, Guam as a USAF Special Handling Cargo Supervisor from 1992-1994, I frequently rejected cargo infested with snails. It's actually quite a problem, especially if the cargo has been sitting outside too long in a tropical environment.
That type of infestation is bad news if it doesnt get caught and these pests reach a country where snails -arent- a problem, causing great agricultural damage to crops and flora.