Microhabitat evaluation and utilization by a foraging predator

► We examined decision-making behaviours of web-building spiders. ► Foraging site selection is a sophisticated, multistep process of evaluation. ► Web-building spiders selected foraging sites based on prey availability. ► Prey availability drives the decision to either complete or abort web construction. ► Existing models do not suitably address foraging by trap-building predators.