Moscovian wrote:
I'd like a fluff reference on that.*
"Recent strains have a shield of ablative chitin over sensory nodes. This burns away during orbital insertion, allowing the Mycetic Spore to draw in on Lictor pheromone trails during the final stages of descent, enabling its cargo to be delivered with greater accuracy."
"These augmentations allow the Mycetic spores a crucial role in the main assault of a prey world. The Hive Mind is now able to reinforce key areas with astonishing quickness, and shield crucial elements of its assault force from incoming fire until the very last moment"
Latest Tyranid codex, P54.
Doesn't sound at all random to me, it sounds highly directed.