Stan has a conniving personality. He is greedy and a sadistic Exterminator. He smokes heavily and is rude to others while smoking and talking to other people as well. He also is very murderous being he tried to destroy the hive of ants Lucas had asked him to do.
Stan is a slob with no regard for his personal hygiene and is very dirty. So dirty that flies fly around his stinky body and clothes. He also has a scruffy face, greasy-looking dark brown hair, and brown eyes. He also dresses in a cruddy red Exterminator suit.
Stan Beals is the local bug exterminator near the suburban area of Las Vegas. He first appeared when he arrived at the house of Lucas Nickle (the protagonist of the film), convincing the little boy to sign a contract of letting him exterminate all of the pests around the Nickle residence before leaving. Nickle agreed to it, since he was accidentally stung by the ant hill while being tortured by an abusive bully.
However, Lucas is alone to deal with the ants after they use a potion to shrink him to their size, forcing him to learn about the ways of the ant. After going through so much training, Lucas learns that the ants can't be as bad as he thought, and that the devil they fear is called the Cloudbreather, which happens to depict a nasty and dangerous bug exterminator. Realizing his mistake, Lucas sneaks back to his house to use the phone to cancel the contract with Stan, but accidentally dials a pizza delivery instead.
The next day, Stan arrives in his van, filled with weapons of pesticide, ready to exterminate the bugs. Lucas apparently convinces several wasps to help the ants fight, but they proved to be no match against Stan's pesticide. However, a beetle and a glowworm managed to go through Stan's pants and bite him in the crotch. This allowed Lucas, his ant friends, and a wasp to inject the shrinking potion onto Stan's butt, misshaping him. A large swarm of wasps come by to attack, and being unable to get back into his van since he is too small to reach the door handles, Stan fearfully pedals away on a stolen tricycle, vowing revenge. As a reward for saving the bugs, Lucas is grown back to his normal size and resume his life. It is unknown what happened to Stan afterwards.
- In a deleted scene, it is revealed that Stan wanted to exterminate the ants until Lucas' father refused, stating that he wasn't interested in Stan's services.
- Another deleted scene showed Stan talking to his assistant that when the ants come together as one, this would be a hard time to take out.
- Stan Beals was voiced by Paul Giamatti (who also played Marty Wolf in Big Fat Liar). He even looks like Paul Giamatti.
- Although he is the main antagonist of the film, his role is very small only appearing briefly in the film's beginning and later in the climax.