For this project you will need only a few materials:
-Enough powdered milk to cover front lawn or desired area
-Knowledge of when the sprinklers are used each day
Step 2: Determine Sprinkler Time
Since it's now spring, the victim will be watering his plants/front lawn. Scout out his house a few days prior to April Fool. Determine when his sprinklers go off. This is crucial since you don't want his to come home to early and discover powdered milk on the ground.
Step 3: Cover the Lawn With Powdered Milk
Once you have determined the sprinkler time window, cover his or her lawn completely with powdered milk.
Step 4: End Product :P
When the sprinklers go off, the powdered milk will turn into actual milk. Therefore, under the sun and after a few hours, it will start to go bad. The milk will curtle and release gross odors. The smell will take weeks to go away. You will be the BEST PRANKER ever!!!!!!!