system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: how do dust baths work?

Like I know chinchillas do it but how does it actually clean them? Like wouldn't it just cover them in dust? And don't they have really dense fur? Won't the dust get stuck there?
gpt
They don't do it to clean themselves of dirt and debris. Because their fur is so dense, if it gets wet for any reason it takes a long time to dry and mold and other things can grow in the fur. The dust helps keep their fur dry by absorbing moisture so they don't get moldy.