Vanguard Wave

As the Tyranids begin their initial invasion, the Hive Fleets vanguard organisms are the first onto the planet, launched by moceptic spores, they arrive in limited numbers at first. Once the Vanguard organisms have arrived on a world ripe for consumption, they begin the process of disrupting enemy defences, disabling important targets and beginning reproduction of other vanguard creatures to signal to the Hive Fleet that a world is ripe for consumption. When vanguard infestations pop up, they are quick, stealthy, organised and initially hard to eradicate, for they take great care to strike unseen and disappear without a trace.