This is what the previous generation advice to me personally. Only send your children to nursery/day care when they are able to speak. So that in case if something happened to the children, they can complaint to the parent.

If you send a children who can’t speak to the nursery too early, you will never know if they children was being abuse in the nursery. Let your close relatives take care of them instead of sending them to the nursery too early.

Pay attention to the children behaviour, if they refuses to go to nursery / center - keep crying , it signifies they don’t felt happy going, someone mistreated them. If they are happy going to the center / nursery, it signifies they are well treated there.