Boophilus microplus (Cau.) has established itself in Australia in an arc across the northern part of the continent, where annual rainfall exceeds 15-20 ins. It extends southwards down the east coast within this zone, but is progressively limited to the coastal region by low inland winter temperatures. Within the favourable zone are areas of reputed tick scarcity (RTS). In sorne of these areas, predation of engorged ticks by ants was sufficiently intense to provide a probable explanation of scarcity of ticks. In other RTS areas the tick scarcity was apparently due to the aridity of the soil surface of hilly areas, in contrast to adjacent tick infested alluvial plains. Sorne evidence is presented against the widely held view that the drinking water consumed by the cattle in the areas is responsible for the reputed tick scarcity. Hypotheticallife-tables are presented, to place the potentiallosses due to ant predation in perspective. Even in tick infested areas, about half the engorged females may be killed by ants and Lycosid spiders.