when she was smaller, she would just grab a ball and mouth it. When she was learning to sit up, I could recline her on some pillows and drop a ball into her lap, saying "Here comes the red/green/etc ball" each time. Now that she's older, we have other fun games. They don't bounce much; so they are good for indoor games. She can sit in my lap about 4-5 feet from the wall, and I can throw the balls against the wall for her to watch them roll back to us.
I bought an old six-compartment muffin tin and put a ball in each compartment for her to take out (she's just starting to try to put them back). When she played in her kiddie pool, the balls would float ... and she'd grab them and mouth .
Be aware that each ball has one hole in it. This makes for fun when you compress the ball and let air blow out the hole into her face. But it also makes cleaning the balls a bit more inconvenient.
I can only imagine some of her saliva has gotten in there, yet I am hesitant to fill them with soapy water because I won't ever get it all out. But this is, IMHO, a minor problem.
