There has been some controversy about whether adult females of social Stego
dyphus disperse by ballooning. Here we show that adult Stegodyphus dumicola
(Eresidae) Pocock 1898 are able to gain up-lift by releasing a very large
number of threads. The threads fan out widely from the spider's body and fo
rm a triangular sheet. This previously unknown ballooning mechanism, enable
s even large spiders to disperse over large distances.