Some other questions to ask are:
Training that the teachers have ??? what the state requires for the teachers or daycare workers.
Looking at the frig is a good idea but some children may have needs that require medication all the time. My son went to a pre school daycare after being in special ed and the school had some special needs children that needed medication all the time so for different health situations. You may want to ask if they ever have special children that require on going medications so not to judge and think all the kids are sick all the time for what maybe in the frig.
See if they have a nurse on duty or what times of they day they have a nurse on duty.
See if you are able to check by a camara online to see the class room. I lived in Florida and had my son at a daycare that had that you could look in on the class if you had the internet anytime.
See if the children yours are able to see each other during the day at all if their rooms will be near each other.
I think you can also call the state and see if any of the schools daycares you look at have had any complaints filed.