If Ratchet came close to the bushes where they were hiding the troopers would stay for quite a while. The best way to kill them was to go far from the bush where they were hiding and then when they came out of hiding, quickly picking them off with a longer range weapon such as the blaster, or just trick them with the Mine Glove. Although the Blarg Bombthrowers were very well hidden among the plant life, they could still be seen while hiding. If the player saw a long, black antenna with a red tip, you could tell which bush the trooper was hiding.