eli5: How does your tongue know where to put itself when you chew so it won’t get bitten?
A combination of evolution and lower brain function. When you walk in normal environment you don’t have to micro manage every step and movement, you have whole part of the brain that manages this task without it becoming a thought. So the tongue would be similar.
We have a sense that’s called proprioception. It’s a sense that among other things informs us about where the body parts are in relation to each other. When you chew your tongue actually does a lot of work you might not have thought about before, it moves the food around and makes sure you do not swallow too early. Your brain uses your proprioception and the sense of touch to move your tongue safely out of the way of your teeth while it does its job with the food. But as we all have experienced, it doesn’t work 100% of the time. Ouch.
Years of practice in getting out of the way before you grew teeth. Not that it’s always successful. I’m in my 40s and recently bit my tongue so hard that it bruised. (Fun fact: tongue bruises heal super quick)