Intra-and interspecific aggression is quite common in ants, from occasional conflicts to large-scale territorial disputes. The "nasty neighbor" phenomenon describes the differential aggressive treatment of neighbors versus foreign intruders. Due to the fact that workers of a given colony meet rival neighbors more often at food resources, they treat them as threats to their colony. The reverse can also happen: the "dear enemy" effect arises when an already known rival is treated less aggressively due to accommodation, than an unknown distant one. In the current study, we analyzed the effect of distance on the aggressiveness of Liometopum microcephalum, a territorial arboricolous ant, towards non-nestmates in two large populations. Our results show that aggression did not increase with distance, but it was higher among neighbors than among workers coming from distant nests. The results of the study are consistent with the nasty neighbor scenario, and do not support the hypothesis that the studied populations would be polydomous systems of interconnected nests.