Visual Communication: Badges
1. Visual communication in the animal kingdom can be either structural or behavioral in nature. Structural adaptations are called badges. These include an animal's coloring -- for example, a male bird's brightly hued feathers can indicate his fitness for mating. A badge can also be the size of a particular body part. A male deer's antlers, for instance, are a sign of power. The bigger the antlers, the more influential the deer.
Visual Communication: Displays
1. Displays are behaviors animals perform for the benefit of other animals, for example, to warn off an enemy or attract the opposite sex. Dogs display submission by tucking their tails and lying on their backs. They display dominance by staring, raising their fur, and baring their teeth.
  
  During mating season, the male lyrebird approaches a female with his impressive tail held up over his head. After his approach, he backs up temptingly, inviting the female to join him on his personal mound of dirt.
Auditory Communication
1. Animals use an infinite variety of sounds to communicate their intentions. Dogs bark and cats hiss to show their displeasure. Coyotes are remarkably vocal canids, using a range of yips, howls, and barks to signal other coyotes in the area, and to mark territory.
  
  Red squirrels are known to make a series of loud rattling sounds, screeches, and yips to threaten intruders, and dolphins have individualized whistles they use to identify themselves.
Tactile Communication
1. Communicating with touch is very important for many species. Touch establishes bonds between mother and infant. It is used to comfort, and also to assert dominance.
  
  Touches that show affection include an animal licking or nuzzling an infant, mutual grooming, mates rubbing against each other or resting in physical contact with one another. A touch that signals annoyance in many species is a nip or snap that doesn't draw blood; a bite without breaking the skin is an even stronger warning.
Olfactory Communication
1. Animals also communicate by leaving their scent behind for other animals – friends and foes – to pick up on. They use scents to announce their interest in mating, to define territorial boundaries, to warn off intruders and predators, and also to attract prey. Most animals use urine to chemically communicate, but many also use scent glands located in the hooves, on the face or close to the anus or scrotum to leave a little bit of themselves behind.
  
  Snakes have a quite ingenious way of smelling things. They use a flick of the tongue to detect scent particles in the air. When they locate a scent, they pull their tongue back in where it makes contact with a special organ in the roof of the mouth that analyses the scent.
Sonar Communication
1. Certain species – primarily marine animals and bats – are able to communicate with sonar (which is an acronym for Sound Navigation and Ranging). Sonar simply makes use of echo, which is why communication with sonar is called echolocation.
  
  Bats produce pulses of high-pitched sounds that are out of human hearing range. But the bats listen for the sounds to bounce off close objects, which gives them information about the immediate environment.
  
  When a whale in the ocean makes a sound, it bounces off objects swimming nearby, and the whale uses those reflected sound waves to find and follow a fish, for example.
Vibrational Communication
1. Vibrational or seismic communication involves sending pulsations through soil or plant stems, and is the preferred communication tool for many insects and even some mammals. The vibrations are created by drumming, pulsing the body, or rubbing body parts together.
  
  Insects exchange low-frequency signals to locate or identify potential mates, during courtship, competitively, or to signal a warning. Predators and prey also detect each other through vibrations, with predators sometimes mimicking the signals of prey in an effort to attract their next meal.