Hatt's vesper rat
otonyctomys hattti latin

Hatt's vesper rat (Otonyctomys hatti), also known as the Yucatán vesper rat, is a species of rodent in the family Cricetidae.

Hatt's vesper rat has a typical rat-like appearance, and closely resembles the related Sumichrast's vesper rat, from which it can most easily be distinguished by its much larger auditory bullae.

Hatt's vesper rat is found throughout the Yucatán Peninsula, in the Mexican states of Campeche, Yucatán, and Quintana Roo, and in northern Guatemala and Belize.