Little Sister Vent
From BioShock Wiki
Throughout Rapture there are numerous holes in the wall surrounded by metallic fixtures. These vents allow Little Sisters access to all areas of the city so they can collect valuable ADAM from corpses. The Little Sisters are the only thing small enough to fit into these vents and crawl through them, therefore they can use them as a means to safely move around the city without a Big Daddy. The design of the metallic plate, which includes stylized leaves and plant stems, insinuates that the vents may all lead - possibly through a pumping system - to Arcadia, transporting oxygen and carbon dioxide to and from them. Some areas of Rapture contain vents that are in disrepair with water flowing over or out of them.
Big Daddies are always awake and vigilant. When they do not have a Little Sister with them, they roam to the nearest vent and pound on its rim. The noise summons a Little Sister out. When the Little Sister is tired of or finished gathering ADAM, she goes back to the vent and the Big Daddy usually helps her up into it. If you use Hypnotize Big Daddy or save a Little Sister after taking down a Big Daddy, she will scurry back to the nearest vent and crawl away. On levels where Jack has already exorcised or harvested every Little Sister, lone Big Daddies roam around and continue to pound on the vents, but no Little Sister comes out. They will show physical signs of aggravation and disappointment, then trudge vainly onward to the next vent.
[edit] Trivia
- In the Little Wonders Educational Facility in Point Prometheus there are signs that were used to help Little Sister learn how to properly use the vents. However, the names of the vents were simplified to seem more innocent/friendly as they are nicknamed, 'Hidey Holes'.
