In the field of animal communication, an alarm signal is an antipredator adaptation referring to various signals emitted by social animals in response to danger. Many primates and birds have elaborate alarm calls for warning conspecifics of approaching predators. For example, the characteristic alarm call of the blackbird is a familiar sound in many gardens. Other animals, like fish and insects, may use other non-auditory signals, such as chemical messages. While visual signs have been suggested as alarm signals, they are easier to pinpoint by predators and less likely to be received by conspecifics, so have tended to be treated as a signal to the predator instead. An animal who signals an alarm is called an alarmer.