Girls, tell me, is it just us like this? The baby keeps sucking on eve…

Girls, tell me, is it just us like this? The baby keeps sucking on everything and laughing at me when I scold her and try to take out what she shoved in her mouth. She starts eating a book, but when I say "ah-ah", no, run away from me and laugh ? She can't understand anything. I don't allow her to climb into the closets, so she doesn't go in there. Only with her mouth like that.