It’s a morning ritual. About 5:00am, my cat goes to her cat scratching post to sharper her nails then, like clockwork, comes in my bedroom, gets on the window sill and begins making a high pitched chattering sound. I call it “talking to the birds.” What is this sound? Even though your cat is a content little indoor kitty, he is a hunter by nature. Your cat is not calling the birds over to play with them but rather, he is watching his prey. Whether it be a bird or squirrel, he will make that high pitched chattering sound. The cat opens his mouth slightly, pulls his lips back, and then opens and closes his jaws very quickly. If he is really excited, he may add a high pitched vocal sound that sounds almost like a cry.  The noise is instinctual. Behavioral specialists have noted the similarity of the noise to one made by cats delivering a special neck bite when killing a bird or small rodent. So your cat isn’t really “talking to to birds” but rather watching is prey even though the only prey he’ll ever get is the one on the end of his cat fishing pole!