Rats are no laughing matter

Scientists, who apparently study rat tickling have recorded some ultrasonic laughter coming from the critters. Now I'm not debating that the rats enjoy tickling, and may even squeal in delight, but laughter is an entirely different thing in my mind. I was recently listening to an interview with a primatologist who said that the only human emotion that great apes may lack is genuine regret. Your pet may look guilty after it's done something it knows is wrong, but that doesn't mean it regrets it. Similarly a rat may squeal when you tickle it, but that doesn't mean it cracks up when it sees another rat slip. I would argue that real laughter necessitates a sense of humour, which is dependent on abstract thinking, and creating scenarios in your head with things or situations that do not exist, something which seems to be notoriously absent in animals. In fact, it is often the incongruity which triggers the laughter, in a sense, it may be a way for the brain to dismiss what it can't interpret or file away...

Nevertheless the article is a fun read. If you do have rat pets, this is how you tickle them effectively: "Tickling various areas of a rat’s body is remarkably effective in generating maximal levels of this ‘‘laughter’’ response. Just like humans who are more ticklish on certain areas of the body (e.g., ribs), young rats have ‘‘tickle skin’’ concentrated at the nape of the neck where they direct their own play activities. Tickling at the nape of the neck consistently produced more chirping than tickling the posterior dorsal surface of the animal, but full body tickle was most effective of all. "