Power
Kids at the pre-K age are hungry for knowledge, love to feel accomplished, and are starting to really form their own identities with their pint-sized peeps. So, while it may not appear daycare workers have a lot of power, they actually do, in many ways.
That's why you're going to have to proceed with caution. The kids trust you. What you tell them is, in their minds, fact. You need to be sure you're actually teaching facts, not your own personal values and belief systems. The exception to this, of course, would be if you were to work in a daycare that is affiliated with a religious institution. Otherwise, leave your personal feelings out of the daycare. Your lifelong hatred of poodles has no business making its way into the lesson plan. Think of the children.
Mind-molding powers aside, daycare workers don't wield much authority—especially where parents are concerned. Parents justifiably feel entitled to a certain measure of control over the way their children are cared for. This might mean some choice words if they think little Timmy has been having too much sugar at snack time.
As the daycare provider, you must toe the line between your style of control and the individual parents' wishes. The customer is always right, and if the advice they asked for conflicts with their ideals, or just isn't what they want to hear, guess who loses? You do. They can bring complaints about you to your supervisors and even get you fired. And that's not going to look great on your résumé.