its the collective mind of all tyranids.

so sure. it has a physical form.
but that form? It's the entirety of the tyranid race.

So what you're saying is... we're going to need a massive gun?

The hive mind is a psychic network running through all Tyranids, there is no one origin from which it emanates. Each nid is like a single cell of a massive organism intent on consuming everything around it. So it is literally legion and the only way to be sure of snubbing it out is to eradicate every last Tyranid in existence.

Not sure exactly how the Night Lords would go about their usual tactics with the nids. They atleast have night vision which would elimanate any genestealers creeping amongst the shadows.

nightvision won't do shit against cloaking.

they're gonna have fun with deathleaper and his lictor buddies...XD

Might be mistaken, but don't the systems include a wide vision array? Heat, electrical, etc.?

lictors have some of the most advanced cloaking in the galaxy. so i would assume they disguise heat and whatnot, at least partially. So yes, but it would still be difficult to pinpoint the lictor for long.

Elimination of synapse creatures and other high value or high threat targets, I guess. Surgical strikes, that sort of thing. Though just because they prefer ambush/skirmish/recon tactics that doesn't mean they are incompetent at conventional warfare. It is simply their preference.

I really to doubt Tyranids give off heat, they don't need heat as far as I can tell. If they needed heat, surely they would have died out long ago?

So why do little nids get scared and go animal mode when I commander or one of the bigger nids dies because the connection is severed I heard so we would only really need to focus on big nids to wipe them out which are swarmed by the smaller ones of course but if you have termi armour np

The etc. included other ranges of vision. The best I can describe would be, think of all the ranges of vision a Predator could see in from the Predator and Alien movies.