The Blood Suckler and its cousin the Bone Suckler are both kamikaze ANMCs, meaning that they self destruct when they get too close or die, which is when they get shot. This can be useful for wiping out multiple groups of Sucklers or damaging Scorpions, Scavengers or Strangers that are in the vicinity. While it is never shown in game, these are the children of the Mind Suckler and theoretically they could develop into the more advanced version.