Please answer the following question about this movie plot. If it's un-answerable, please output "No answer". Question: In what form are the aliens camouflaged? Movie plot title: Apollo 18 Movie plot: In December 1974, the crew of the cancelled Apollo 18 mission is informed that it will now proceed as a top secret Department of Defense (DoD) mission disguised as a satellite launch. Commander Nathan Walker, Lieutenant Colonel John Grey, and Captain Ben Anderson are launched toward the Moon to place detectors to alert the United States of any impending ICBM attacks from the USSR. Grey remains in orbit aboard the Freedom command module while Walker and Anderson land on the moon in the lunar module Liberty. While planting one of the detectors, the pair take moon rock samples. After returning to Liberty, the pair hear noises outside and a camera captures a small rock moving nearby. Houston claims the noises are interference from the ICBM detectors. Anderson finds a rock sample on the floor of Liberty despite having secured the samples. During further lunar exploration they discover footprints that lead them to a bloodstained, functioning Soviet LK lander, and a dead cosmonaut in a nearby crater. Walker queries Houston about the Soviet presence, but he is told only to continue with the mission. The following day the pair find that the flag they had planted is missing. Their mission complete, the crew prepares to leave, but the launch is aborted when Liberty suffers violent shaking. An inspection reveals extensive damage to Liberty and non-human tracks that Walker cites as evidence of extraterrestrial life. Walker feels something moving inside his spacesuit and is horrified as a spider-like creature crawls across the inside of his helmet. Walker disappears from view and Anderson finds him unconscious outside of Liberty. Walker later denies the events. A wound is discovered on Walker's chest; Anderson removes a moon rock embedded within him. The pair find themselves unable to contact Houston or Grey due to increased levels of interference from an unknown source. Anderson speculates that the true intention of the ICBM warning devices is to monitor the aliens, and that the devices are the source of the interference,...
The answer to this question is:
Moon rocks