Mud is a favorite with them. Especially with the trucks.
Water play, they can't get enough time with. I fill the tub up at least 4 times. Owl was thirsty so he stuck his face by the hose and took a drink. Then he wanted to fill his cup up so he stuck it under the sprayer. Found out about the force of water.
Story time is best done outside. They'll pull up the chairs and gather round me.
Our days are active.