Past research suggests that category-based induction flexibly draws on different kinds of knowledge in different contexts, and that different kinds of knowledge may differ in accessibility. The present study investigates the degree to which knowledge accessibility mediates context-sensitive induction by examining the effects of time pressure on inferences about novel properties of animal species. Participants were told about a novel gene or a novel disease that was true of one category of animals, then rated the likelihood that taxonomically, ecologically, and unrelated animals had the same property, under speeded or delayed conditions. Property effects were observed for taxonomically related species independent of time pressure, but were only observed for ecologically related species in the delayed condition. These results suggest that time pressure selectively restricts access to ecological knowledge, and that knowledge access is critical for context-sensitive inductive reasoning.