Day care centers are much more regulated than family day care, and by regulation there are always 2 carers in a room at the one time
Also, family day care doesn't regulate who else can be at the house when the kids are there - I still remember the time a family day care mum came into work for a massage and told me
She'd left the kids at home with her husband! I was totally shocked!
If you go with family day care try word of mouth and make sure you are really comfortable with them.