system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How exactly does cling film work?
gpt
Static electricity.   

When you pull it off the roll, some electrons get pulled from one layer to the one peeling off, making some bits positive and others negative.   

When you wrap it back over itself, those positives and negatives attract each other and it sticks.   

That's why it doesn't work if you leave it for a while before wrapiing or try to stick it to metal - the electrons go back to the right place making things neutral again.