M.J.
I agree with the pp. Make sure it's quite serious and that you've already mentioned your concerns to the daycare provider (at least give the person a chance to make changes). Basically, by filing a complaint, you will make it so the provider can't take on any future business (anyone who calls to check on the license will get your report). If you feel the situation is that bad, then definitely file a complaint, however.
We had a scary daycare provider a few years ago who went nuts when we gave two weeks notice and refused to give us the rest of the month's payment back (a significant amount of money ... many hundreds of dollars). She thought we were conspiring in some way to ruin her life and her child's financial stability. Seriously. In the end, we dropped it because we worried about our safety if we reported her or went to small claims court. She was bonkers and this was the first we recognized it (how scary to think our kids were in her care and we didn't know). You can't always tell how people will react.