A tiger's tail is about 3 feet in length and is used for balance when it runs through sharp turns. A tiger's tail is also used as an aid to communicate with other tigers.
When a tiger is aggressive, its tail lashes violently from side to side while the tiger keeps its head low and its eyes wide open. Conversely, a relaxed tiger has a relaxed tail. Also, a tiger holds its tail low with its ears laid back and teeth baring when it feels threatened. When it investigates its surroundings, the tiger's tail is held high while its ears are upright and alert.
Tigers also communicate through scent. A female tiger rolls on the same area where a male has urinated and then urinates there herself if she is interested in mating.
Tigers communicate through vocalization by roaring and chuffing as well. A roar will be used when taking down prey, signaling sexual receptiveness, keeping other tigers away or bringing another tiger into their territory. These roars can be heard 1.8 miles away. Chuffing sounds like a soft "brrr" sound, according to SeaWorld.org. Chuffings are friendly vocalizations used for greetings between tigers that can only be heard at close range.