Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:Insects are ideal systems to investigate the interplay between infection and behavior.(12,14) The fruit fly Drosophila is especially amenable to these studies, as it is one of the best developed model systems for host-pathogen interactions(15) and behavioral ecology and genetics.
Category: