Tali'Zorah nar Rayya was born in 2161 aboard the starship Rayya to Rael'Zorah, a member of the Admiralty Board of the quarian Migrant Fleet. After reaching the threshold of maturity, she departs the Migrant Fleet on her Pilgrimage, the traditional quarian rite of passage into full adulthood. On her travels, she begins hearing reports of geth, who had never ventured beyond the Perseus Veil since driving her people into exile, and decides to investigate. Though young, Tali is a mechanical genius. The quarians are a nomadic species of humanoid aliens known for their skills with technology and synthetic intelligence. Since their homeworld Rannoch was conquered, the quarians live aboard the Migrant Fleet, a huge collection of starships that travels as a single fleet. Quarians are generally shorter and of slighter build than humans. Quarians have an endoskeleton, lips, teeth, and two eyes with eyelids and tear ducts. Their ears or ear analogues differ in a noticeable fashion from those of humans, with references made to "what [passes] for the quarian version of an ear". Their eyes can see into the ultraviolet end of the spectrum; their suit HUDs can show information in those wavelengths. Quarian facial structure and hair makes them the most similar to humans out of all known sapient species. The most distinguishing feature of quarian biology is their weak immune system, compounded by centuries of living in sterile environments. As a result, all quarians by necessity dress in highly sophisticated enviro-suits, to protect them from disease or infection if they are injured. Their suits can be compartmentalized in the event of a tear or similar breach to prevent the spread of contaminants (similar to a ship sealing off bulkheads in the event of a hull breach). Along with their suits, quarians also have extensive cybernetic augmentations integrated into their bodies. A quarian's lifespan is roughly equal to a human's, but is prone to be less if infection breaks into the suit.