In the chapter of the linguistics textbook that I am supposed to be reviewing there is a description of an experiment involving chinchillas. The researchers wanted to see if chinchillas could perceive speech sounds like humans, so they trained them to run across the cage whenever they heard [b] and stay put whenever they heard [p]. Then they played a lot of sounds that were halfway between [b] and [p] and watched the chinchillas be really confused.
I've decided that if this whole CIA thing doesn't work out, chinchilla linguist is my new dream job.
I mean really. Just look at them.