SNIFF TEST. “The main avenue of ant communication is chemical, and cuticular hydrocarbons have been shown to be particularly important in mediating nest-mate recognition. Several social parasites have developed the capacity to exploit this circumstance, penetrating ant societies by displaying chemicals that mimic those of their hosts. This strategy can be accomplished either by acquiring the host cuticular compounds through direct body contact (chemical camouflage) or by synthesizing them (chemical mimicry).”
http://www.pnas.org/content/112/4/1101.full