Butterworts are also known as “pings.” In Latin, Pinguicula means “little greasy one” because the leaves look and feel greasy. The greasy substance is actually a sticky trap for small insects like fruit flies and gnats.
The small insects could be attracted to the shiny appearance of the leaves or the musty smell. After they land on the slimy leaves, they realize that the leaves are very sticky. Once stuck, the plant will start to secrete digestive juices that quickly dissolve the insect. The leaves then reabsorb the tasty bug slime.