Trachops cirrhosus locates prey by eavesdropping on communication signals. Merlin Tuttle and Michael Ryan showed in the early 1980s that the bat approaches speakers playing the calls of palatable frog species and avoids those playing calls of toxic ones, such as the cane toad. Discrimination is by call structure, not by contact.
This creates a direct conflict for the frog. Male tungara frogs, Engystomops pustulosus, can add chucks to the end of the basic whine, which makes the call more attractive to females and also easier for the bat to localise. The elaboration is under opposing selection from mate choice and predation, and males call less elaborately when bat risk is high.
The bat is also a demonstrated social learner. Naive individuals in captivity have learned to approach an initially unattractive artificial call after observing an experienced bat do so, and can retain the association for a considerable period. What remains unclear is how much learning shapes prey preferences in wild populations, where individual experience is difficult to track.