The Sivaoans are related to the Eeiauoans like Vulcans are related to the Romulans. The Eeiauoans had been banned from the planet. Since the Enterprise, under the command of James T. Kirk, made first contact with the Sivaoans, the communication between the two races has been restored.

Tails to Ennien received her pre-Starfleet schooling on Sivaoa. She was well-trained in everything except the use of computers, as the Sivaoans see no need for them.

Like most Sivaoans, she has a perfect memory. Tails to Ennien has the ability to recall conversations as accurately as any computer, but is also able to recall what everybody smelled like at the time (e.g. scared). She can't remember graphics accurately. Because of her superior sense of smell, she is also a very good tracker and can find any intruder on the ship by smell alone.

Tails uses her tail almost as a third arm. She also uses it to show her emotional state. Tails is the granddaughter of Brightspot to Ennien. Brightspot was the one who encouraged her to go to the Academy. Even though she has been trained to work with computers, she still doesn't really like to use them. Tails prefers to rely on her own mind to remember things instead of putting it into a machine.

She has a playful personality, loves to pull practical jokes on people, which she refers to as "pulling people's tails." But when it is needed, she can be very serious and very focused on the job.