A group of butterflies is officially called a kaleidoscope, although they are sometimes referred to as a swarm. Groups of caterpillars are called an army.
The world is home to around 20,000 species of butterflies. Mexico has a population of about 2,000 specie while the rest of North America hosts more than 700 species. In the United States, any particular area is home to about 100 species of butterfly.
Most butterflies have a life span of about a month, with some smaller species living only for one week. The longest-living butterflies include the monarchs and mourning cloaks that live for around nine months.
Some longer-living butterflies migrate during the year, flying south during the cold winter months and returning to the north in the spring and summer. The routes the butterflies follow vary by species.