I’m being currently subjected to a Peppa Pig marathon as I watch my nephew. They are visiting the zoo.
Some kinds of animals are clearly “people” - like Peppa and the zookeepers. But other animals are non speaking - animals. They showed non talking penguins eating fish - are fish not “people” either?
The zookeeper is a lion who confuses the teacher - some sort of gazelle - with a wildebeest as a running joke, which seems to suggest that he thinks of her as food.
Some of the jokes in this show seem targeted to adults, which makes no sense, as absolutely nothing in this show is watchable to anyone above the age of 4.
Some of the jokes ARE targeted at adults. For the writers are perfectly aware that people like you will be watching it with little kids, at least on occasion. Throwing an occasional bone to an adult may be the difference between the child getting to watch the show and the adult ushering them off to something else.
As far as the who gets to be sentient and who doesn’t question: there’s probably not that much thought put into it. The writers sit around and spitball ideas at each other. They make a list of things that would be engaging for kids yet not too expensive to animate and not too long or complicated too make them lose interest. Someone probably said what about a trip to the zoo. When it came time to do the one for the zoo they said what animal should be in the zoo. What things interest children? Penguins, what do kids see them do with the penguins well they feed them. So now you need non-sentient penguins and non-sentient fish. I’m fairly certain they’re just trying to make it up as they go along and make sure they don’t alienate kids or parents too badly.