Prey Adaption
(Rule)Description: If a Malanthrope Brood is involved in any close combat which results in an enemy unit or units being destroyed in combat, it may not perform a Sweeping Advance but instead stops to feed on the dead. From the end of that phase onwards all friendly Tyranid units gain the Preferred Enemy (all units from the same Codex as the destroyed enemy unit) special rule while they remain within Synapse range of the Malanthrope Brood - Note this includes the Malanthrope Brood too.