Broadcast 22 November 1990, this programme details how fighting - both physical and psychological - is used for food, land or to gain a mate. Territorial conflict is demonstrated by the hummingbird, and Attenborough illustrates its aggressiveness by placing a stuffed specimen nearby, only to have it speared by its opponent s bill. The midas cichlid on the other hand, has no weapons to speak of, and so uses its mouth to hold on for trials of strength. By contrast, the forelegs of a mantis shrimp are powerful enough to crack the shell of another crustacean: therefore disputes or courtship are fraught with danger.