Skatole alone (before: upper left and after: lower right) or in combination with DEET, BDR-4 (methyl jasmonate) or BDR-5 (γ-dodecalactone) was applied at the constant dose of 0.1 μM. DEET, BDR-4, and BDR-5 were applied at 1 mM, 0.5 mM, 0.25 mM, 125 μM, 60 μM, 30 μM, and 15 μM (from top to bottom). At higher doses, the outward currents elicited by DEET or BDR-4 are larger than the inward current generated by skatole, thus generating a net outward current.