system
Given the following post, respond as if you're commenting on Reddit:
human
How do trick candles work?

What keeps them lit, or makes them able to re-light after being blown out?  How does blowing them out NOT work?
gpt
You know how when you blow out a regular candle there is still a little bit of a glowing ember at the tip of the wick?  Well trick candles also contain in the wick some magnesium which ignites at the temperature that that ember is glowing at causing a flame which reignites the rest of the wick.