Wings are part of the exoskeleton and attached to the thorax, and butterflies bask to heat up their wing muscles for flight. Given these facts, what organism's instruments of flight are part of the exoskeleton and attached to the thorax among the following options:
- insects
 - organs
 - barnacles
 - butterflies
 - to move people
 - honeybees
 - it needs them
 - Electric devices


 

    butterflies     