El Blanco is... Confused.

It must be admitted that belonging to a species which has barely evolved since the precambrian era, and being a giant worm at that, that the brains of Graboids are... Small. Only just large and complex enough to actually allow the huge creatures to function in truth. Let alone try and search for the meaning to a question. So it should come as no surprise to learn that El Blanco, smart as he was for a Graboid, had even less of an idea about what underwear was than before he pantsed the siesmology major. One thing he did notice was that she seemed kind of frantic to pull her shorts back up. A difficult thing to do when she was rolling around on the ground, tripping all over herself in her frantic efforts to pull her pants up. All she was actually doing was giving the young(ish) Graboid a free show with her cotton panty covered ass.

All the vibrations she was making were also reminding El Blanco that he was getting hungry.