Sid is a mean, aggressive pre-teen who spends his time torturing small animals. Seth is his lanky little yes-man who hides behind his buddy's bulk when shouting insults. They love to bully total nerds, so living in Science City must be like Christmas for them. Of the two, Sid is clearly the more dominant, pushing Seth around nearly as much as he does his actual targets. They attend the same school as the crass-yet-good-natured Billy and Fred, their dopplegangers.