Individuals do not count in a hive society. Member of the swarm exist to offer their life to the hive; these specific necrophages more literally than most. While they may look just like an alternate strain to the common necrodrone, they can be far more dangerous: they spontaneously combust when near their target.
The xml file lists the self-destruct delay time is between 1-2 for normal and .5 to 1.5 for the elites. One could assume this is a randomized number of seconds.
Target Priority: Most populated room (within a certain range)
Mob ID: Mob_N_Kamikaze / Mob_N_Kamikaze_Elite
Note: * When a Kamikaze blows, it will deal great damage to heroes, significant damage to modules and npcs, and only slight damage to other monsters in the room.
* As Kamikazes have no attack value, they will not attack other mobs when troubled.