Q: How do you make an orange giggle?
A: Tickle its navel!

Explanation: Oranges are a delicious fruit.  One type of orange is the navel orange.  Navel is also a word used for your belly button.  If someone tickles your belly button, it might make you giggle.

This joke is funny because it plays with the double meaning of the word navel- a type of orange and a belly button.  And if you want to giggle at an orange you could watch an “Annoying Orange” video.