You know those little black bugs that you sometimes see when washing rice before cooking? They’re known as rice weevils, and they take advantage of rice grains for laying eggs and feeding. Well, it’s this freeloading behaviour that brought about the re-use of their name to describe people who don’t work and rely on other people for food, scroungers.
Here’s a straightforward example of how you might use this word to describe a scrounger:
tā méi gōngzuò, yīzhí zài jiālǐ dāng mǐ chóng
He’s doesn’t work, and just freeloads from his family