‘Bubbling’ behavior, or the regurgitation of liquid from the crop through droplet formation on the proboscis, has been observed in many nonblood feeding dipterans. One factor that has been identified as a cause for ‘bubbling’ is the concentration of the solution flies ingest. The hypothesis presented in this paper states that male flies ingesting more dilute solutions will exhibit more bubbling behavior than those that ingest a less dilute solution. Concentrations tested were a high concentration of 80% sucrose solution and a low concentration of 20% sucrose solution. Males only were tested to avoid any confounding effect of the females need for energy sources for reproduction. Male flies that ingested the 80% sugar solution showed 45% of the flies tested bubbling, which was significantly different from the flies that ingested 20% solution, which had only 5% of the flies bubbling. No significant weight loss or percentage of weight loss was observed between bubbling and nonbubbling flies for either sugar solution concentration. Results comparing a high and low concentration of sucrose do not support the theory of elimination of excess water loss to concentrate dilute solutions or the “dilute solution hypothesis”. Other factors, not identified previously, that could contribute to bubbling, are changes in osmolality, utilization of blood sugar (i.e., trehalose), and the regulation of the proventricular valve.