Coccinellidae (/ˌkɒksɪˈnɛlɪdiː/) is a widespread family of small beetles ranging in size from 0. 8 to 18 mm (0. 03 to 0. 71 inches). The family is commonly known as ladybugs in North America, and ladybirds in Britain and other parts of the English-speaking world. Entomologists prefer the names ladybird beetles or lady beetles as these insects are not classified as true bugs.