Tractors have big wheels, and it's hard for farmers to see little kids walking up to them. Even when tractors are not moving, playing on them is dangerous. You can fall off or cut yourself on sharp parts. Stay away from them. Take a grown-up with you when you want to go around farm animals.
Some farmers raise fish in ponds.
Turtles, frogs, and birds, live near ponds, too. Ponds may look like swimming pools, but they are not. Always go with an adult when you want to visit a pond. Never swim or fish alone. Billy and Susie wandered far from the house while they were playing.