How do bats get around at night, how do they avoid obstacles? How do they fly in the inky blackness inside caves, and how do they find food in the night sky? They use a mysterious sense not possessed by humans, a form of biological sonar, sometimes called "echolocation" or "biosonar". Dolphins and toothed whales (e.g. killer whales) also possess biosonar, as do some species of cave-dwelling birds, and possibly some species of shrews and seals. Don't be misled about what biosonar is.....

Now explore the games, exercises and activities in these sections:

		Chapter 1: The Sonar Signal Listen to some of the diverse sounds produced by animals for the purposes of sonar: dolphins, bats and horseshoe bats.
		Chapter 2: The Discovery Scientists were investigating bats and their strange sensory abilities 200 years ago.
		Chapter 3: How it Works Through the auditory system of a bat or dolphin: the design of sonar signals, how they are received as echoes, and how the echoes are processed to form images.