Within agricultural landscapes higher amounts of semi-natural habitat and fragmentation of forest appear to have positive effects on bat species richness and activity, however the way crops are arranged (configurational heterogeneity) or their diversity (compositional heterogeneity) may also have a role. Smaller field sizes should increase both the accessibility and quality of foraging habitat. The diversity of crop types may also benefit bat communities by creating more diverse, abundant, and temporally stable communities of prey insects. We conducted acoustic surveys in agricultural landscapes in Eastern Ontario to test the predictions that bat species richness and activity should increase with increasing compositional and configurational heterogeneity of crops. Field size appeared to have mixed effects on bat activity levels. Total bat activity and activity of several species was higher in landscapes with higher diversity of crops. We hypothesize this is because diverse crops create more temporally stable prey communities.