Simplify the following text for a Grade 11 native English-speaking person.
Original: Butterflies are a natural monophyletic group , often given the sub-order Rhopalocera , which includes Papilionoidea ( true butterflies ) , Hesperiidae ( skippers ) , and Hedylidae ( butterfly moths ) .
Simplified: Butterflies are a natural monophyletic group . They are often placed in the suborder Rhopalocera , which includes Papilionoidea ( true butterflies ) , Hesperiidae ( skippers ) , and Hedylidae ( butterfly moths ) .