Do not feed the kittens. As long as the mother is breastfeeding them she will eat their waste.
If you feed them outside food she will stop and you will have to teach the kittens how to use the litter box.
Once that happens you should be able to put them all outside and the ones that stick around as long as you feed them a little bit we'll both hang around and keep your place rodent free as well as take care of snakes and as long as you keep them inside the house you will need to feed them completely unless you have a supply of mice rats and other things that they will eat