We examined patterns in the abundance and species richness of arthropods in Australian rangelands, and explored the potential for using different biotic groups (plants, vertebrates and arthropods) as indicators of grazing impact. The most diverse and abundant arthropods in pitfall-traps were ants (Hymenoptera: Formicidae). Other moderately abundant taxa included Collembola, Diptera and Araneae (spiders). Ants and spiders were unusual in that their abundance remained generally high, regardless of vegetation type or season. Ants showed consistent patterns of change in species composition along gradients in grazing intensity, but Collembola, Coleoptera and Orthoptera did not. However, understorey plants and birds were more efficient indicators of grazing impacts.