Rice Krispies (known as Rice Bubbles in Australia and New Zealand) is a breakfast cereal marketed by Kellogg's in 1927 and released to the public in 1928. Rice Krispies are made of crisped rice, which expands to form thin and hollowed out walls that are crunchy and crisp. When milk is added to the cereal the walls tend to collapse, creating the famous "Snap, crackle and pop" sounds.