Synapse

If your Army Faction is Tyranids, while a
Tyranids unit from your army is within 6" of
one or more Synapse models from your army,
that unit is said to be within Synapse Range of
your army.
Each time a Tyranids unit from your army takes
a Battle-shock test, if it is withinSynapse Range
of your army, take that test on 3D6 instead of
2D6.