A new study digs into the pros and cons of two different methods for testing potential bed bug repellents: a harborage test and a barrier test. Shown here is the harborage test setup, in which bed bugs were placed in a dish with two harborages, each consisting of a pair of filter papers (b and c), one treated with repellent and the other untreated. (Image originally published in Krüger et al 2021, Journal of Economic Entomology)