Dumping behaviour of Australian desert ants ( Melophorus bagoti ) (Hymenoptera:Formicidae)

The Central Australian desert ant Melophorus bagoti maintains ground-nesting colonies in the semi-desert habitat. These ants manage waste by dumping items outside the nest. To examine this process, we placed organic and non-organic materials that are associated with either low or high pathogenic risk around or into the nest and observed the nest’s response. We found that generally, ants dumped high-pathogenic-risk materials (dead larvae, dead ants of the colony, foraged food, moth, and non-nest cicada exoskeleton) further from the nest than low-pathogenic-risk ones (sand, buffel grass, cookies), with the exception of (organic) larval shells from their own nest, which were also dumped close to the nest. This pattern of dumping suggests that these ants choose their dumping distance based on how spoilable the experimental materials are.