Your baby's now exploring objects by shaking them, banging them, dropping them, and throwing them before falling back on the tried-and-true method of gumming them. The idea that you do something to an object is beginning to emerge, an activity center with lots of things your baby can bang, poke, twist, squeeze, shake, drop, and open will fascinate her. Your baby will also be fascinated with toys that have specific functions, such as phones. If she can't hold it up to her ear herself, do it for her and pretend to have a conversation. Over the next few months, she'll start to use objects for their intended purposes brushing her hair, drinking from a cup, and babbling on her play phone. Also, at this stage, your baby likes to see things fall down, get picked up (by you, of course), and then get thrown down again. She's not trying to drive you mad. She just finds the spectacle interesting and naturally wants to see it again and again.