The adults are very quiet near the nest but the fledglings make loud gargling sounds as they are fed. The discovery of an owl or cat sets off a sort of mob hysteria. By hiding a microphone among a flock of crows it has been found that they also talk in whispers. Animals do not have a true language even though they can communicate with one another by sounds and gestures. Each kind has a certain number of inborn signals for expressing its feelings but these are not words.
All human infants laugh or cry to express their emotions without being taught.
Their language must be laboriously learned, one word at a time. A baby chick hatched in an incubator and reared away from all other chickens makes the same calls and behaves the same as chicks hatched and reared by a hen. The only noticeable difference is that young cockerels learn to crow sooner and better when they can hear an old rooster. Some apes can utter as many as thirty different sounds which a patient trainer can learn to understand. They seem to be on the verge of true speech.