The one that we test is a raisin, but anything like that around ten to twelve months. And each of those is showing greater ability to handle even smaller things that require more skill. I don't think you should try to specifically stimulate various parts with the exception of language, which I'll get back to in a second. But the idea is to give them various kinds of toys, allow them to play with different size objects, again, making sure they're all safe for the baby who might choke on something. Language is a different story.
Language occurs because children hear other language.
And it's critical from the beginning to talk to your baby, to read to your child, to sing to them, to have them hear the spoken word, to have that as part of the interaction, because that's what gets them to learn how to make sound. And language can be worked into every other aspect of these babies lives. As you're doing everything. And appear very disturbed, and what's critical is that language is part of the way that we interact with other people around us. And babies need to interact.