Board Thread:Warhammer 40k General Discussion/@comment-86.7.138.66-20130615215334/@comment-38.116.192.98-20160502151341

The norn-queens are like the vices of the hive mind and create new tyranids along with interpreting the hive minds orders and keeping control over the hordes instincts. Also the tyranids are built purely to survive and don't seem to care for anything else but survival so an alliance is unlikely.

Also its probable the tyranids were created artificially since they adapt faster than any living being and are efficient at what they do meaning they were created or are just really experienced with wars of attrition and adaption and were just a natural evolution. Maybe the old ones did make them as a last ditch effort or as a means to an end to wipe a slate clean or screw over the necrons as a last laugh. All we have to do is wait and see what nightmares spill from the void.