A't'trr

"We are also here."

- The A't'trr talking through O'Neill

The A't'trr are an advanced alien hive mind encountered in the early days of Stargate SG-1.

Appearance
The A't'trr are actually thousands of microscopic creatures impossible to see with the naked eye. Collectively they flourish in ultraviolet light; revealing electric blue tendrils wherever they have spread. When feeding, they glow.

Abilities and Technology
The A't'trr feed on heat and oxygen. They can withstand extreme temperatures such as direct exposure to a blow torch, or the heat of an explosion. They claim that an explosion that would destroy the SGC would be enough to allow them to spread across the planet.

Once they reach a large enough number they can express their hive intelligence allowing them to communicate with other lifeforms. Despite their small size they are an advanced race as event by the remains of the city on their home world and their Orb.

In the Series
Prior to encountering SG-1, the A't'trr discovered that their homeworld was becoming uninhabitable. Unable to save their world they created a cryogenic device called the "Orb" to cryogenically preserve the species. They planned to wait until another species would come and take the orb through the Stargate to a new home.

The Orb was eventually discovered by SG-1 who took it back to Earth to study. Exposed to the atmoshphere of a living world the Orb soon started to activate. Panicking, the SGC decided to send it back through the gate. Realising what they intended to do, the A't'trr released several spikes from the orb imbedding them into the gate room and trapping O'Neill who was pinned by one of the them.

Discovering the spread of the microbes through the base, the SGC feared they were dealing with an alien contagion and took several steps to try and combat the threat, only to meet with failure each time. Time was running out, with the base's systems set to self-destruct. During this time Daniel noticed some of the orb symbols on the computer repeating in sequence, and came to the conclusion they were dealing with a sapient organism that was attempting to communicate.

Revealing his findings both Carter and Daniel realised that Jack's stabbing had been no accident since the force alone should have been enough to kill him. Coming to the conclusion the organism did it on purpose they decided to heat the gate room and cut Jack's medication so the organism could use Jack as a mouthpiece to communicate.

It is soon discovered that while the organism is friendly and has no desire to harm humans it will not allow itself to be returned to its former dead world. With time running out Daniel gets the idea to send it to another world SG-1 was set to visit. A primordial Jungle world with enough recources for the aliens to survive without interfering with the native life.