Repulsion of flies by a volatile chemical, benzaldehyde.

<p>Method 1: A) Flies begin near benzaldehyde at start. Data are presented for each of the 3 parts of the assay. Mean ± S.E.M. for 3 experiments. B) Control without benzaldehyde. Mean ± S.E.M. for 3 experiments. Method 2: C) Flies randomly distributed at start. Data are presented for each of the 3 parts of the assay. Mean ± S.E.M. for 7 experiments. D) Control without benzaldehyde. Mean ± S.E.M. for 6 experiments.