Orb-web spiders may anticipate their future prey environment by detecting the presence of prey and adjusting their web building behavior accordingly. Here we investigate the effect of different prey sizes and density on the web size and mesh height of the orb webs constructed by Argiope keyserlingi. The experimental design allowed the transmission of prey vibrations but prevented any capture. We found that A. keyserlingi constructed webs more frequently in the presence of prey, but did not alter the web size or mesh height of their webs.