 In the Treatise of Animals Condillac further developed his views. He repeated what he had said in the Treatise of Sensations: animals are capable of pre-linguistic reflection, just like humans. They judge and compare ideas and by these means discover how to do things necessary for their survival. By this kind of reflection, all animals learn the proper use of their organs, in order to flee what is dangerous and search what is useful to them. Reflection is at the origin of the formation habits, like the one that makes us avoid a falling object that is heavy. As the actions originally done deliberately by reflection are gradually turned into habits, “the animal touches, sees, walks without reflecting on what it is doing” (Treatise of Animals, II.1). Thus, the more habits are formed, the less need there is for reflection. What is called instinct in animals is not an innate pattern of behaviour, but rather a well-developed habit (Treatise of Animals II.5). This habit bears witness to the effort of inventive reflection that originally taught animals the use of their organs: birds have to learn how build their nests and beavers have to learn how to build their shelters (Treatise of Animals II.2).