Creep *creep  = dynamic_cast<Creep*>(itemsInRange.at(0));
    double lowestHp = creep->getCurrentHp();
    int index = 0;
    for(QList<QGraphicsItem*>::iterator it = itemsInRange.begin(); it != itemsInRange.end(); ++it, ++i) {
        if(dynamic_cast<Creep*>(*it)->getCurrentHp() < lowestHp)
            lowestHp = dynamic_cast<Creep*>(*it)->getCurrentHp();
            index = i;
     }


    /* attack target with lowest hp*/
    Antibody antibody;
    antibody.setPos(towerMid);
    map()->addItem(&antibody);