Never expires.
Have you learned about metaphors and similes? Extra credit is available to students who find and capture metaphors and similes from their reading. A reward (extra credit points) is currently available for the capture of these valuable creatures.
Include the metaphor or simile, where you found it, and a page number (if appropriate).
For example, this sentence from The Outsiders uses a metaphor: "I couldn't have gotten much cooler without turning into a popsicle." (page 53) It's not literally true that he would turn into a popsicle. This is figurative language -- a metaphor -- comparing two unlike things to help the reader understand what it was like to be that cold.
On page 54, we find this simile:
"Johnny was scared to death. I mean it. He was as white as ghost . . . "