A swarm of space probes has been sent from a planet of intelligent trees to attempt to detect intelligent life on Earth. The probes use sound and light to communicate with any life forms in the vicinity, and report their findings back to the home planet, where results are analyzed.

Background
U-Ram Choe
Bjorn Schulke
Discovery Channel - Alien Planet
Yucca Mountain project

User Scenario
The probes are going through a sound and light display routine designed to discretely attract attention.

When a person approaches, the display increases in intensity. When the person reaches out to the probe, it follows the motion with corresponding changes in light and sound. After a few seconds, the probe "proposes" games, expecting the person to follow changes in sounds and light by moving in front of the sensors. The probe is keeping score, assessing the "intelligence" of the interaction, but this is invisible to the person. When the score passes a certain threshold, other probes in the vicinity become active, and participate in the interaction.

In a remote location, there is a display showing the "intelligence" scores over time. The connection between this and the probes only becomes clear after some scrutiny.

Implementation
Construct a series of "probes" designed to detect intelligence, by broadcasting patterns of light and/or sound, and looking for a response. If found, the patterns become more complex. Also, a remote location is notified that intelligence has been found.

The probes are made of wooden twigs and branches, hollow gourds, cast urethane and various electronic components. The electronics are mostly microcontrollers, digital potentiometers, multicolor LEDs, Sharp infrared sensors and XBee data radios.

Conclusion
[preliminary]

Attribution of intelligence (or lack thereof) based on purely mechanistic criteria is often wrong.