Think about any work in the scope of the position that might not typically be part of a daycare structure: laundry, cooking, cleaning, juggling different age kids, etc...
Also daycare teachers do have other adults around, so are your candidates prepared to make that switch to a position w/ significantly less adult interaction?
Will they be driving your child(ren) and if so, in whose car?
What ages have they worked with (specifically - there are big differences developmentally between 18 month olds and 4 year olds).
Etc...
Think hard about the differences and structure some of the interview around that.