Observation of a grey squirrel ( <i>Sciurus carolinensis</i> ) suggests that some rodents can vomit

While an emetic response (vomiting) is an adaptation common to many mammals, rodents are typically believed to lack the ability to vomit. However, few rodent species have been directly tested for an emetic response, and therefore, the inability to vomit may not be universal among rodents. While opportunistically recording wildlife in North Carolina, we observed a grey squirrel ( Sciurus carolinensis Gmelin, 1788) retching and then expelling gastrointestinal contents (i.e., vomiting). Arboreal squirrels are neurologically and morphologically different from many other rodents, and we discuss how these differences may allow for the observed emetic behavior. We discuss how our finding may impact the use of rodents as models for human health research and potential impacts to rodent management.