When spiders take over: the expulsion of giant Amazonian ants from their nest

Spiders have been documented using nests of various ant species. In this study, we recorded the non-harmonious use of a nest and the expulsion of giant Amazonian ants from their nest by a Diplura spider. Both species inhabit South American forests, including the Amazon rainforest and Cerrado. This event took place in the northern Cerrado of Brazil during the rainy season. The expropriation process lasted 13 days, beginning with the simultaneous occupation of the anthill and culminating in the complete eviction of the ants. Over the last two days, we observed intense ant activity at a second entrance to the anthill and the construction of a new nest. We propose that the funnel-web spider was using the ant nest as shelter. However, the simultaneous coexistence may have been limited due to the spider web blocking an entrance and dietary overlap leading to competitive exclusion.