The 26 hydrocarbons identified from Iridomyrmex humilis comprise 0.24% of the body weight of the insect. They include the normal alkanes, C14 to C27, and a number of alkenes and 3- and 5-monomethylalkanes in the range C14 to C20. The presence of 4-methylhexadecane is noted. Two of the constituents, heptadecane and (Z)-nonadec-9-ene, comprise 80% of the total.