Tenn. R. Evid. 406
Advisory Commission Comments.
Tennessee has long admitted animal habit. Copley v. State, 153 Tenn. 189, 281 S.W. 460 (1925), is the leading case. Authorities supporting admissibility of human habit and business custom are collected in Tennessee Law of Evidence §.
The second paragraph defines habit and routine practice, emphasizing the need for a "regular response" when a person, animal, or organization is faced with a given situation.