Season 20, episode 8: "The Burns and the Bees"
You can watch it here:
Sure, it's silly- it's the Simpsons! But leave it to sweet little Lisa to take on a good cause!
I've been a Simpsons fan for years, and still remember the broadcast of the Christmas episode back when I was about 10 years old. I have enjoyed the show ever since, because it makes me laugh and usually has a good message, too.
This episode was especially well done and I will even confess, the scene with the dead bees and Groundskeeper Willy playing "Amazing Grace" on his bagpipe brought a tear to my eye.