What is the title of this certain old animated/cartoon movie?

I used to own this movie on VHS as a kid, the name is escaping me and it's driving me crazy. It is a cartoon movie, I'd say it came out between the 60s and the 80s. The plot is basically a small orange bug who gets cast as a construction worker in his society at this big bug ceremony, yet all he wants to do is play in this band (maybe the flute?). I know it's random, but some memorable scenes are when this bug goes into a tunnel and encounters a blue and red two headed worm who always argues with itself. Oh and all the bugs in the movie can detach their butts and roll them around. I want to find this movie and get it as a bday present for my sister...it would provide a lot of nostalgia. Any suggestions as to what the title is?