Summary.A more exact terminology than that current is suggested for behaviour having the effect of deflecting intruders from a bird's nest or chicks. The general term “diversionary display” is used to describe all such activities, and a distinction is made between “distraction display” and displacement activities having a diversionary function. Various sub‐categories of distraction display are distinguished–injury‐simulation, chick‐simulation, eccentric deportment and advertising distraction display. Attention is called to the possibility that a number of displacement activities habitually performed when an intruder menaces the nest or chicks may have divers