Reproductive glands...
*EXCESSIVE DRUMMING KICKS IN* GGGGGGGGGHHHHHHHHHHHHHEEEEEEEEEEAAAAAUUUUUUUUUUUUUUUUUGGGGGGGGGGGGHHHHHHHHHHHHHHHHHHHHHHHHHH
This song for a long while has been my favorite Nirvana song, and it's easy to see why. It's one of the catchiest songs I've ever heard in my life.