sleeping in class

I understand that my class can be boring sometimes. But I absolutely love when I give an assignment and they have had 10-15 minutes to work on it and I announce, "Okay, 2 more minutes!" and a student pops his head up and says, "Nah, miss, I ain't finished!" and expects me to give him more time to finish the assignment that he chose to sleep through. Ugh! (Like the run-on sentence? I grill my students on that too!)