Hk^IE18 mutants display an increased wing beat frequency and a subtle, yet statistically significant, decrease in DLM firing rate. The regularity of DLM spiking is also affected, with a significant increase in the DLM inter-spike interval CV.

The rate of habituation of the giant fiber escape pathway is reduced and attainment of five consecutive failures is delayed in Hk^IE18 flies compared to wild-type. The refractory period of the long-latency response is shorter than normal. The short-latency response of the dorsal longitudinal muscle occurs earlier than in wild-type flies.