Prey-predator interaction is mediated by prey defences and prey-predator size differences, but also by the characteristics of the predator, such as speed, subduing mechanisms, and defensive mechanisms against prey retaliation. Ricinuleids are particularly slow-moving arachnids, without venom but with a heavy armour covering the body. We looked at how such poorly known and unusual arachnids would deal with prey of different sizes, armours, and defensive mechanisms. We offered ants, millipedes, worms, and termites in the laboratory. The acceptance rate of ants was not different from other prey species, including unprotected termites; only 35% of the millipedes were accepted and, regarding prey size, larger worms tended to be less accepted than smaller worms (but the trend was not significant). The armour of ricinuleids likely protects them from ant stings, while well-armoured millipedes had only legs removed but were not killed, and the lack of venom may explain why smaller worms are preferred. The unusual prey-capture mechanism of ricinuleids provides a model to test how different predatory strategies interact with prey defences.