Heterozygotes and homozygotes show resistance to halothane in an inebriometer assay (an assay of geotactic and postural behaviour) compared to wild-type flies. Decapitated flies lose the halothane resistance phenotype.
Individuals are able to remain standing upright in the presense of halothane.
In the absence of anaesthetics individuals do not show obvious defects in phototaxis, geotaxis, longevity or morphology. When exposed to anaesthetics individuals do not freeze, as na mutants do, but simply take longer to respond to the anaesthetic.