Mice acquire flavor preferences during shipping

Vigorous motion can cause rodents to develop flavor aversions and show other signs of malaise. We tested whether a flavor aversion could be induced by shipping mice from an animal breeder to a test site. Boxes of 12 male C57BL/6J mice were shipped approximately 950 km from Bar Harbor, ME to Philadelphia, PA by truck. For some boxes, the gel provided for hydration was flavored with almond and for others it was flavored with banana. After the journey, the mice were individually housed and allowed to recover for 5 days. They then received a choice between the two flavors of gel. Contrary to expectations, mice preferred the flavor they had previously ingested during shipping. Controls given flavored gel under similar conditions but while stationary did not show a preference. These results suggest that mice find shipping or its sequelae pleasurable. If mice are travel sick this must be inconsequential relative to other components of the shipping experience.