The diet **data** used in this study was collected from a comprehensive search of the available literature, searching exclusively for bats present in Britain (B. barbastellus, E. serotinus, M. bechsteinii, M. brandtii, M. daubentonii, M. mystacinus, M. nattereri, N. leisleri, N. noctula, P. auritus, P. austriacus, P. nathusii, P. pipistrellus, P. pygmaeus, R. ferrumequinum, R. hipposideros, and M. alcathoe). Google Scholar and the Web of Knowledge databases were mined for published bat diets up to January 2016 (Scopus was not used as it does not index many papers older than 1970 [26]). The terms searched for using the Boolean "AND" were: "Diet", "Food", and "Prey", with "Bat", "Chiroptera", and the names of each of the species. In some cases, it was appropriate to exclude certain studies. Typically, this was due to the reporting of diets with only presence/absence data, as it was not possible to convert these to numerical **data** without the introduction of bias. Papers were also excluded if they did not detail diet break down, if they described controlled experiments (i.e. captive fed bats), if stable isotope analysis was used, or they did not use primary data.