From Creatures Wikia
The suffering creature will tell you that it's trying to perform an action on a agent, which will often be 'eat elevator'. However, the green indicator of the creature's attention will be not visible. This is because the creature has its attention on itself, and the green indicator goes under the red one. The indicator will go under the red one if the object is close enoungh, i.e under the creature or the creature itself.
No script is active, while everything creatures do requires a script, and the only time a script is not active, is when the creature is making a new decision, which will only require a few ticks. The scripts that are activated, are involuntary actions, including fainting.
If the attention of the creature is diverted to another agent that will satisfy a different high drive, or if they perceive the agent that the brain wants, they will instantly snap out of it. Because of this, it is rarely observed in a room full of activity and items, and it more often happens to creatures roaming the empty hallways.
The cause of the EE syndrome is unknown.