US military is attempting to develop a new style "insect robot" to replace the human soldier to go wherever he can't. The greatest trouble this project has fallen across is how to enable the robot to fly freely like an insect, said an official of the Pentagon . The Pentagon is seeking for the cooperation with scientists in hope of developing a new technique by which people can control the insect's flight direction and pass on the information its eyes or other organs catch through the equipment set in its body, the official said. It is thus designed that a tiny controlling chip will be equipped in an insect's body when it is in chrysalis . As the insect grows, the cut made when fixing in the chip will be recovered. The chip will exist in forever. Scientists believe this won't influence the insect, sound growth or the functions of internal organs. The _ target of the project is to set up a global system, in which the insect robots will be stationed in all parts of the world and stick to their posts till a new instruction is received. At that time the military can receive from all over the world clear image information within about 5 meters of the insects and that of a special target within 100 meters. Years ago, Defense Advanced Research Projects Agency of US DOD  spent $3,000,000 carrying out a plan for training bees to detect landmines. But, no new progress has so far been made. "According to the scientists, there is still enormous difficulty in technology in turning it into reality, such as the insects reproduction , their adaptation to the surroundings and temperature and so on. However, this project is really challenging. If successful, it is equal to making countless small drone ,"said the official of DOD. Of the following technical problems, which is the one the scientists can't solve so far?
They can't keep sound growth of the insects. They can't ensure the insects to produce their young. They can't fix a chip in an insect. They can't make sure the internal organs function well.