Answer:
put sticky plastic wrap under the toilet seat. when they go to the btroom, they will spill. dont get caught also put clear jello at the bottom of the toilet and when some one in your family can't flush the toilet and the will be laughing
another great prank is to open up the lid that leads to the toilet's mechanics and put yellow dye in the thing that contains water that will go into the toilet, so when it flushes, it will appear to be broken!
This a really cool site showing 101 ways to fool others on April.The pranks are really good and easy.Have a look at it.I promise you won't regret
Enjoy April Fools day