colonies of the weaver ant ("oecophylla smaragdina") are able to recognize a greater proportion of workers from neighbouring colonies as non-colony members. when recognized as non-colony members, more aggression is exhibited toward neighbours than non-neighbours. banded mongoose ("mungos mungo") groups vocalize more and inspect more scent samples in response to olfactory cues of neighbours than strangers. it has been suggested that increased aggression towards neighbours is more common in social species with intense competition between neighbours, as opposed to reduced aggression towards neighbours typical for most solitary species. furthermore, animals may respond in this way when encounters with intruders from non-neighboring colonies are rare and of little consequence.