Flies show a very low and unreliable native responsiveness to sucrose stimuli applied to the tarsus.

Blocked or impaired in learning, with respect to several types of conditioning tests used on groups of flies or on individuals, including those involving electric shocks (FBrf0037264) or exposure to flies (mated females, immature males) that in wild type induce poor courtship subsequently (FBrf0038075). Flies may be generally debilitated and tests involving habituation or sensitization to sugar stimuli gave unreliable results (FBrf0038637).