Elephant Toothpaste

"Mommy, we made elephant toothpaste in school, and it exploded all the way across the gym!" my daughter said.

"What?"  I said.  "First of all, what is elephant toothpaste?  And second, why was it explosive?"

"I don't know," she said.  "Mad Science came to school today.  They mixed all this stuff up, and then they brushed a poster elephant's teeth with it.  Then it exploded.  And I helped!"

"Great.  What else did you do?"

"We made this huge fire with chemicals."

"Uh, okay.  Was the fire department notified?"

She shrugged.  "Can we make elephant toothpaste at home?"

"What's in it?"

"I know there's yeast and some other chemicals."

"We're not making elephant tooth paste."

Now I'm going to search the cupboards and make sure I don't have any yeast lying around.