Angels who eat butterflies (Clione limacina and limacina helicina)
Some animals fly. This and 'a fact known to all. They get rid of the constraints of the force of gravity 'that would keep them anchored to the ground and conquer graceful three dimensions. Being able to remain suspended in the top allows their movements without limits in all directions, and look seraphic from creatures that continue to crawl on this earth, like us. A prerequisite to win the freedom 'of the flight and' owning wings for propulsion and direction, to take off and glide. Every creature and 'emerged victorious from the battle against gravity', such as birds, insects and bats, had to reinvent its wings from existing structures, usually the forelegs. It 's not easy to come to that, many try, fail and glide.
Some snails fly, and this is' a fact that few people know. Snails with wings are called pteropods, which means winged feet because it 'right from the foot, the structure on which their colleagues crawl, which have evolved wings of these delicate creatures. In less poetic terms flying snails belong to the group of gastropods opisthobranchs, meaning "with gills behind the heart." There are two main groups of snails with wings, Sea butterfly and Gymnosomata, each comprising several species, distributed worldwide.