The Collaborative International Dictionary of English v.0.48:
myrmecophile \myrmecophile\ n. (Biol.) An organism such as an insect that habitually shares the nest of a species of ant. [WordNet 1.5]WordNet (r) 3.0 (2006):
myrmecophile n 1: an organism such as an insect that habitually shares the nest of a species of ant