I agree with Bookworm. Children who have a lot of control at home and rule the roost there, are often ticked off and complain when they are not the ones in control at daycare, school, etc.
I wouldn't take it personally, because it sounds like you are running an excellent daycare and providing him and the others with activities and outings and lots of opportunities for fun, along with healthy food, time to rest and recharge, etc... all things that children need, regardless of whether or not they think they want it.