Fool.

Kara: "Ms. Stromgren, there's a shark behind your back!"

Me: "What?!"

Kara: "April Fools!!"

Me: "Kara, April Fools Day is on April 1st. Today is April 16th. You have to wait a whole year to say that!"

Kara: "Ms. Stromgren, you have a bug on your head. April Fools!"

Can't say I didn't try...