A plurality of individual toys, at least a first one of which generates acoustic signals and at least a second one of which receives acoustic signals. When the second toy receives acoustic signals from the first toy, it responds, for example, by generating a sound and/or controlling its motion. In a preferred embodiment of the invention, the toys flock and/or form a procession of toys which follow a leader toy, for example a mother goose and a plurality of following and preferably quacking goslings.