Smell and Laugh, Tickled Rats

This study tells of a new (and perhaps the first) advance in the effort to explore the relationship between rats and laughter and odor:

Odour Conditioning of Positive Affective States: Rats Can Learn to Associate an Odour with Being Tickled,” Vincent Bombail, Nathalie Jerôme, Ho Lam, Sacha Muszlak, Simone L. Meddle, Alistair B. Lawrence, and Birte L. Nielsen, PLoS ONE, vol. 4, no. 6, 2019: e0212829.

The authors report: “This work is the first to test in a fully balanced design whether rats can learn to associate an odour with tickling.”

The report does not specify whether this effect also happens in mice.

The University of Edinburgh produced a press release about the rat work.