Tenajes operate as the main technicians in charge of "terraforming" the local atmosphere to make it alien-compatible. Tenajes generally work alone but also may be found in pairs, likely indicating an area where more work needs to be done or perhaps even that one may be a trainee under the tutelage of another Tenaj. They are quick, smart, and likely to ambush an unsuspecting Marine. One would be smart to keep an eye upon their Proximity Map to help avert their devious surprises. Despite representing a formidable threat, the Tenaj are not heavily armored and despite their intellect are also likely to turn their backs towards their foe. A clever Marine will use their M-343 or a stolen Alien Assault Cannon to blow a few holes in whatever sides they happen to show their foe, and pick up any charge packs they ultimately drop to make up for spent ammunition.
- Despite being given the title "main technicians" of the invasion force, the Otrebor also have this title, indicating that perhaps Otrebors supervise the Tenajes, as Otrebors are more powerful creatures than Tenajes and are found later in the game. It could also mean that the Tenaj take care of the initial stages of terraformation while Otrebors take care of the later stages.