 Ants of this genus prefer to inhabit grasslands , forests , heath , urban areas and woodland . Nests are found in Callitris forest , dry marri forest , Eucalyptus woodland and forests , mallee scrub , in paddocks , riparian woodland , and wet and dry sclerophyll forests . They also live in dry sandplains , and coastal plain . When a queen establishes a new colony , the nest is at first quite simple structurally . The nest gradually expands as the colony grows larger . Nests can be found in debris , decaying tree stumps , rotten logs , rocks , sand , and soil , and under stones . While most species nest underground , M. mjobergi is an arboreal nesting species found on epiphytic ferns of the genus Platycerium . Two types of nests have been described for this genus : a simple nest with a noticeable shaft inside , and a complex structure surrounded by a mound . Some species construct dome @-@ shaped mounds containing a single entrance , but some nests have numerous holes that are constantly used and can extend several metres underground . Sometimes , these mounds can be half of a metre ( 20 in ) high . Workers decorate these nests with a variety of items , including charcoal , leaves , plant fragments , pebbles and twigs . Some ants utilise the warmth by decorating their nests with dry materials that heat quickly , providing the nest with solar energy traps . 
