The release of the Jerry Seinfeld movie Bee Movie triggered an in-depth exploration of how the laws of anthropomorphism have to work in movies to avoid breaking the willing suspension of disbelief.
As Mark Kermode explained, the problem with Bee Movie was that, like Antz or A Bug's Life, it developed a world in which bees all drive cars, talk to each other in English, and have developed elaborate equipment for the manufacturing and storing of honey - which is fine - but then it suddenly has one of the bees being able to talk to a human in English. The moment this happens, the rules of anthropomorphism are broken and too many questions pile on top of each other for the film to sustain its own internal logic. Why are the bees riding around in actual cars? How are they wearing real jumpers? Have bees been able to talk to us in English all this time? Are they like the German baby in the famous joke?
Finding Nemo, which generally avoided most of these issues, nonetheless runs into a massive issue when it turns out Dory can read English. Since this is the way that Nemo is in fact found, it is deeply problematic and takes the audience out of the film.
In Alvin And The Chipmunks, the issue of the anthropomorphism rules is addressed early on, when Jason Lee's character asks "can all animals talk?" and one of the chipmunks says, "well..."
Mark defended Cars, however, when a listener suggested that it too broke the rules, explaining that it didn't because it was set on a world without people.
At one point Simon Mayo demanded, "where are these rules written down?" Mark responded by asking "where is the rule of gravity written down?" Although Simon didn't know, a listener did - the rule of gravity is written down in Newton's Principia. However, at least Mark can now say that the Rules Of Anthropomorphism is now written down on Witterpedia. Which is a work of equivalent stature, clearly.