A key benefit of being near to others is access to information. Animals often live in environments where resources are distributed in patches that exist only temporarily. In such an environment, a single individual has a very low rate of finding a resource patch if they search independently. When large numbers of individuals search at the same time, however, the probability that one of them finds one of the patches is considerably larger. If individuals are able to monitor and use the discoveries of others in their own search, they can increase their own rate of finding resources.
Many of the mechanisms underlying information transfer are the same across species. Underlying all information transfer is some form of positive feedback: one individual finds food, a second moves towards the first individual and then still a third moves towards the second and so on. This chapter uses a couple of simple mathematical models of positive feedback to provide a reference point for different forms of information transfer. These models help us classify information transfer seen across species.
Living in a communal nest or den provides a good opportunity for information transfer, and in some cases may be the reason communal living has evolved (Zahavi 1971). Individuals returning to the nest with food also carry with them information about its location and quality. This information can be used by nestmates. In social insects, sophisticated signals have evolved to actively communicate food discoveries. Such signals have also evolved in some birds and mammals, but they are not a necessary requirement for information transfer. Communally nesting animals can also use passive cues, such as flight direction and smell, to identify where food has come from.