Crisp rice cereal, or puffed rice, is rice that has been puffed light and airy under heat and pressure, giving a crunchy, largely neutral-flavored cereal.
The puffing process was developed in the early 1900s (patented in 1902) and was commercialized as a breakfast cereal soon after. It's eaten with milk as a cereal, and used as a crunchy add-in for bars, coatings, and confections such as chocolate-and-rice-cereal treats.
Similar puffed-rice snacks appear in other cuisines, including Japanese arare and Indian murmura.