[1.10.2] Spawning particles when an mob is hit?

I just can't seem to make it show up  Please help.

My code:

	@SubscribeEvent(priority = EventPriority.HIGHEST) //Function: Displays "blood" when an entity is hit
	public void onHit(LivingHurtEvent e) {
		if (e.getEntity() instanceof EntityMob) {
			EntityMob mob = (EntityMob) e.getEntity();
			mob.worldObj.spawnParticle(EnumParticleTypes.BLOCK_CRACK, mob.posX, mob.posY, mob.posZ, Math.random() * 0.2 - 0.1, Math.random() * 0.25, Math.random() * 0.2 - 0.1, 137);
		}
	}

Thanks!